The Danger of the Cain Serpent-Seed Error

"For we have not followed cunningly devised fables, when we made known unto you the power and coming of our Lord Jesus Christ, but were eyewitnesses of his majesty...Knowing this first, that no prophecy of the scripture is of any private interpretation. For the prophecy came not in old time by the will of man: but holy men of God spake [as they were] moved by the Holy Ghost" (2 Peter 1:16, 20-21).
"This witness is true. Wherefore rebuke them sharply, that they may be sound in the faith; Not giving heed to Jewish fables, and commandments of men, that turn from the truth" (Titus 1:13-14). 
"Preach the word; be instant in season, out of season; reprove, rebuke, exhort with all longsuffering and doctrine. And they shall turn away [their] ears from the truth, and shall be turned unto fables" (2 Timothy 4:1-2). 
“As I besought thee to abide still at Ephesus, when I went into Macedonia, that thou mightest charge some that they teach NO OTHER DOCTRINE, NEITHER GIVE HEED TO FABLES AND ENDLESS GENEALOGIES, which minister questions, rather than godly edifying which is in faith: so do. Now the end of the commandment is charity out of a pure heart, and of a good conscience, and of faith unfeigned: From which some having swerved have turned aside unto vain jangling; Desiring to be teachers of the law; understanding neither what they say, nor whereof they affirm (1 Timothy 1:3-7).

CHURCH LEADERSHIP

"And he gave some, apostles; and some, prophets; and some, evangelists; and some, pastors and teachers; For the perfecting of the saints, for the work of the ministry, for the edifying of the body of Christ: Till we all come in the unity of the faith, and of the knowledge of the Son of God, unto a perfect man, unto the measure of the stature of the fulness of Christ: That we [henceforth] be no more children, tossed to and fro, and carried about with every wind of doctrine, by the sleight of men, [and] cunning craftiness, whereby they lie in wait to deceive; (Ephesians 4:11-14).
As I begin this critique of the Cain Serpent-Seed doctrine (which has been around for quite some time), I want it to be understood that correcting doctrinal error by rightly dividing the Word of God is part of the leadership ministry spelled out in Ephesians four. Anyone truly called by God to one of the five-fold ministry offices (apostle, prophet, evangelist, pastor, or teacher) has the mandate from the Lord to address erroneous teachings in the body of Christ. The Divine calling to any of these offices is accompanied by a powerful encounter with the Lord Jesus, confirmation from other proven men of God who have truly walked in those callings for years, and Holy Spirit-enabled fruit of the five-fold office/offices will become evident. And without a doubt, I can say that God called me to the offices of a prophet, evangelist, pastor, teacher, and church planter starting in 1987 and the fruit and supernatural gifts of the Holy Spirit have been evident for 30 years.  Thus, I do not apologize or slink away from my responsibility to …reprove, rebuke, and exhort with all longsuffering and doctrine (2 Timothy 4). 

I mention all of this not to boast, but to give understanding of why the Lord compels me to address errors in the body of Christ as I do. It is not because of pride or thinking that I am perfect or always right about everything. It is simply part of the responsibilities of true God-called, five-fold ministers.  There are many serving as teachers, preachers, and even pastors these days that are not called to one of those five-fold offices of church leadership. Some admit that they are merely researchers or “truth seekers” and as commendable as those pursuits are, they do not carry the same weight of responsibility or same authority as God ordained five-fold leaders. In 1 Corinthians 14 Paul wrote that “ye may all prophesy,” but that does not mean that everyone who gives a word of prophecy stands in the office of a prophet. The same goes for teachers. Just because someone leads a Sunday school class or teaches on a radio show it does not make them a five-fold teacher/elder in the church. Every Christian should preach the gospel and try to lead others to Jesus Christ, but that does not make every Christian a five-fold evangelist. 

This is not to say that Christians (who are not called to these leadership positions) should not share the gospel of Jesus Christ or teach the Word of God, but rather, they should be connected and accountable to elders that are true five-fold ministers who can help them stay in sound Biblical doctrine. There are too many “para-church ministries” (which is an oxymoron) that don’t have true five-fold elders. This leaves people without a true church home and accountability. I will probably receive hate-mail for this introduction because there is such a disdain for “organized church” and biblical leadership/submission to authority these days. Nevertheless, Christians don’t get to throw out Biblical principles just because they don’t like them or because some have abused their positions and authority. Here are a few verses to support what I have said:
Remember them which have the rule over you, who have spoken unto you the word of God: whose faith follow, considering the end of their conversation. Jesus Christ the same yesterday, and today, and forever.Be not carried about with divers and strange doctrines. For it is a good thing that the heart be established with grace; not with meats, which have not profited them that have been occupied therein…Obey them that have the rule over you, and submit yourselves: for they watch for your souls, as they that must give account, that they may do it with joy, and not with grief: for that is unprofitable for you” (Hebrews 13:7-9, 17).
The ELDERS which are among you I exhort, who am also an elder, and a witness of the sufferings of Christ, and also a partaker of the glory that shall be revealed: Feed the flock of God which is among you, taking the oversight thereof, not by constraint, but willingly; not for filthy lucre, but of a ready mind; Neither as being lords over God's heritage, but being examples to the flock. And when the chief Shepherd shall appear, ye shall receive a crown of glory that fadeth not away. Likewise, ye younger, submit yourselves unto the ELDER. Yea, all of you be subject one to another, and be clothed with humility: for God resisteth the proud, and giveth grace to the humble. Humble yourselves therefore under the mighty hand of God, that he may exalt you in due time: (1 Peter 5:1-6). 
“Paul, a servant of God, and an apostle of Jesus Christ, according to the faith of God's elect, and the acknowledging of the truth which is after godliness; In hope of eternal life, which God, that cannot lie, promised before the world began; But hath in due times manifested his word through preaching, which is committed unto me according to the commandment of God our Saviour; To Titus, mine own son after the common faith: Grace, mercy, and peace, from God the Father and the Lord Jesus Christ our Saviour. For this cause left I thee in Crete, that thou shouldest set in order the things that are wanting, and ordain ELDERS in every city, as I had appointed thee: If any be blameless, the husband of one wife, having faithful children not accused of riot or unruly. For a bishop must be blameless, as the steward of God; not self-willed, not soon angry, not given to wine, no striker, not given to filthy lucre; But a lover of hospitality, a lover of good men, sober, just, holy, temperate; Holding fast the faithful word as he hath been taught, that he may be able by sound doctrine both to exhort and to convince the gainsayers. For there are many unruly and vain talkers and deceivers, specially they of the circumcision: Whose mouths must be stopped, who subvert whole houses, teaching things which they ought not, for filthy lucre's sake. One of themselves, even a prophet of their own, said, the Cretians are alway liars, evil beasts, slow bellies. This witness is true. Wherefore rebuke them sharply, that they may be sound in the faith; Not giving heed to Jewish fables, and commandments of men, that turn from the truth (Titus 1:1-14).

CONFRONTING ERROR

From the beginning of my call to the ministry in 1987, I have endeavored to always point people back to the rightly divided truth of God's Word as found in the preserved Canon of the 66 books that make up the Holy Bible. I have done that because I have found the Holy Bible and the gospel of faith in the atoning blood of Jesus Christ and the power of His resurrection are the ONLY TRUTHS that can set people free from sin, sickness, and Satan. The first book I wrote called Grace Abuse deals with the false doctrine of “once saved, always saved no matter what.” I went through the Scriptures and systematically proved that “once saved, always saved” or “unconditional eternal security” no matter how a believer chooses to live is a false doctrine. My book called Tongues of Fire deals with the error that the gifts of the Holy Spirit ceased after the Apostles or Canon of Scripture was completed. And my 2012 book, The Polluted Church from Rome to Kansas City confronts the errors of contemplative mysticism, eastern religious techniques and demonic counterfeits that have taken over many Charismatic/Pentecostal ministries today.

The Holy Scriptures and sound Biblical doctrine leads to true salvation found only in the Jesus Christ of the Bible. And I can testify that there is power in the truths of the Holy Bible and the name of Jesus Christ of Nazareth. I have seen thousands saved, miraculously healed, and set free from demons in the name of Jesus by putting into practice the principles of the Canon of Scripture. I have personally witnessed the dead raised, the deaf hear, the cripple walk, all stages and kinds of cancer vanish, and very dramatic exorcisms through the Lord Jesus working in my life and ministry. Hence, I know the fruit of sticking to and believing God’s preserved Word as found in the 66 books of the Bible.

However, just getting someone saved, healed, or even delivered from demons is only part of the battle. False teachers and false doctrines creep into the body of Christ constantly. These deceptions are designed by Satan and his demons to lead believers away from God's Word which always leads to spiritual bondage or worse. Another side-effect of false doctrines is the division it causes among Christians. Often the division is blamed on the person trying to correct the error instead of the one who put forth the false teaching. I can’t count how many times I have been accused of being unloving, prideful, or harsh because I preach or teach unashamedly against doctrines that are not Biblical. However, a leader who truly loves people will address these issues and do it with zeal because someone’s eternity may depend on it. 

The Cain Serpent-Seed doctrine is one of these false doctrines. It causes unnecessary division between well-meaning believers and starts naïve Christians down a very dangerous path of deception. I say “dangerous” because the interpretation methods, sources of origin, and theological gymnastics that one must accept in order to believe that this doctrine is Biblical, opens the door for more false teachings that use the same principles to come up with erroneous conclusions. It’s like teaching a beginning golfer the wrong techniques to swing a golf club and then expecting them to go out and shoot under-par golf the rest of their lives. It’s not going to happen. Bad fundamentals equal bad results for years to come. The same is true for Bible study and how we establish sound doctrine.

GENESIS IS CLEAR

The Cain Serpent-Seed doctrine teaches that Eve had sexual relations with the Serpent (Satan) in the garden of Eden and the result of that encounter was a pregnancy that produced Cain. The claim is that these descendants of Cain ("the serpent-seed") are still with us today. For some of you reading this right now, you just thought, “What kind of craziness is that? I have never seen that in my Bible.” And you would be correct. This doctrine is NEVER stated in the Bible. In order to come to this conclusion, one must accept wild speculation as fact. One must apply verses to Cain that never mention him or the idea that he was the offspring of the fallen angel Satan. I do believe that a "serpent-seed" called the Nephilim and the Rephaim exists today per Genesis 6 and other passages. However, they have nothing to do with Cain or Eve having sex with the Serpent. Genesis 4 could not be clearer that Adam and Eve had sexual relations and produced Cain and Abel:
"And Adam knew Eve his wife; and she conceived, and bare Cain, and said, I have gotten a man from the LORD. And she again bare his brother Abel. And Abel was a keeper of sheep, but Cain was a tiller of the ground" (Genesis 4:1-2). 
The Biblical text in Genesis NEVER states, hints, or implies that there was a sexual encounter between Eve and the Serpent. Teachers of this false doctrine arbitrarily transform the eating of the fruit from the Tree of the Knowledge of Good and Evil into a sex-act. That is quite the leap because the Bible is clear that BOTH Adam and Eve ATE the fruit from the tree. 

“Now the serpent was more subtil than any beast of the field which the LORD God had made. And he said unto the woman, Yea, hath God said, Ye shall not eat of every tree of the garden? And the woman said unto the serpent, We may eat of the fruit of the trees of the garden: But of the fruit of the tree which is in the midst of the garden, God hath said, Ye shall not eat of it, neither shall ye touch it, lest ye die. And the serpent said unto the woman, Ye shall not surely die: For God doth know that in the day ye eat thereof, then your eyes shall be opened, and ye shall be as gods, knowing good and evil. And when the woman saw that the tree was good for food, and that it was pleasant to the eyes, and a tree to be desired to make one wise, she took of the fruit thereof, and did eat, and gave also unto her husband with her; and he did eat. And the eyes of them both were opened, and they knew that they were naked; and they sewed fig leaves together, and made themselves aprons. And they heard the voice of the LORD God walking in the garden in the cool of the day: and Adam and his wife hid themselves from the presence of the LORD God amongst the trees of the garden. And the LORD God called unto Adam, and said unto him, Where art thou? And he said, I heard thy voice in the garden, and I was afraid, because I was naked; and I hid myself. And he said, Who told thee that thou wast naked? Hast thou eaten of the tree, whereof I commanded thee that thou shouldest not eat? And the man said, The woman whom thou gavest to be with me, she gave me of the tree, and I did eat. And the LORD God said unto the woman, What is this that thou hast done? And the woman said, The serpent beguiled me, and I did eat.” (Genesis 3:1-13)
Eve saw that the tree was pleasant to look at and good for FOOD not an orgasm. So, this doctrine turns the perfect, sinless woman that God made for Adam into a perverted adulteress who had a freaky attraction to a reptile with legs. This Serpent-Seed error also turns Adam into a bisexual pervert if "eating the fruit" of that tree was really a sex-act with the "Piercing Serpent." Thus, this teaching of Eve having sex with the Serpent and Cain being the "seed of the Serpent" can only be believed by rejecting the obvious literal interpretation of the Biblical texts in Genesis. Instead, one must allegorize (thus changing) the entire account of the fall of Adam and Eve and that is why this doctrine is so dangerous. It sets a precedence for bad self-styled interpretation of the Bible and encourages the use of demonically inspired books outside of the Bible.

THE BIBLE VS. ANCIENT TEXTS

Basically, if people can accept the Cain serpent-Seed error as truth, they are set up for further deception. It encourages people to spiritualize or allegorize any part of the Bible they wish. This is Satan's trick to get people to change the plain meaning of God's Word. It is not surprising that this Cain Serpent-Seed doctrine is found in the book of Jewish fables and occult mysticism called the Zohar. The Zohar first appeared in the 13th century. The Jewish legend (fable) claims that a rabbi went into a cave for 13 years in the 2nd century AD to study the Torah and was inspired by the prophet Elijah to write the Zohar. Among other things, the Zohar teaches the practice of looking for deeper meaning in the Scriptures beyond the plain text. Imagine that! However, this Serpent-Seed doctrine appears to have originated from the early Gnostic heretics. It was recorded in the 3rd century AD Gnostic Gospel of Philip which is NOT part of the inspired Word God. 

There is only one ancient copy of the Gnostic Gospel of Philip which is written in the Coptic language. It was discovered in a cave at Nag Hammadi, Egypt in 1945.  This book was in a single "book" bound with the Gnostic Gospel of Thomas. The Gnostics were total demonically-inspired heretics whose doctrines were being circulated in the latter part of the first century. The Apostles began to confront the Gnostic errors in their epistles like Colossians and 1, 2, & 3 John. The second century church leader, Irenaeus battled these false teachers and wrote volumes against their heresies. The Gnostics departed from Biblical truth in many of their teachings. For example, the Gospel of Philip fabricates the falsehood that Mary Magdalene was the chief counselor and/or wife of Jesus and He loved her more than all of His disciples:

"As for the Wisdom who is called 'the barren,' she is the mother of the angels. And the companion of [the saviour was Mary Magdalene. [Christ loved] Mary more than [all] the disciples, and used to] kiss her [softly] on her [hand]. The rest of [the disciples were offended by it and expressed disapproval]. They said to him "Why do you love her more than all of us?" The Saviour answered and said to them, "Why do I not love you like her? When a blind man and one who sees are both together in darkness, they are no different from one another. When the light comes, then he who sees will see the light, and he who is blind will remain in darkness."

The Gospel of Thomas that was contained in the single codex with the Gospel of Philip teaches such nonsense like Saying 114 which states, “Simon Peter said to them, ‘Let Mary leave us, for women are not worthy of life.’ Jesus said, ‘I myself shall lead her in order to make her male, so that she too may become a living spirit resembling you males. For every woman who will make herself male will enter the kingdom of heaven.’” This statement smacks of the demonic transsexual agenda and is absolutely insane! It also teaches that Jesus was not human or in the flesh which is the very definition of the spirit of antichrist in 1 John 4! Another teaching from the Gospel of Thomas is that Jesus is not the prophesied Jewish Messiah. How much more does one need to see to discern that these non-canonical books are demonic? Yet some Christians are using these Satanically-inspired writings to validate false doctrines of devils that end up causing confusion and division in the church. 

Here are the quotes from the occult Zohar and the Gnostic gospel of Philip that first taught the Cain Serpent-Seed doctrine: 

The Zohar in Bereishis 36b says, "When they begat children, the first born was the son of the (serpent's) slime. For two beings had intercourse with Eve and she conceived from both and bore two children. Each followed one of the male parents and their spirits parted one to this side and one to the other and similarly their characters."

The Gnostic Gospel of Philip vs. 46 says, "Adultery occurred first, then murder. And (Cain) was begotten in adultery, for he was the son of the serpent. Therefore, he became a manslayer just like his other father (the serpent), and he killed his brother (Abel)."

It should be evident that we cannot accept “ancient texts” like the Zohar and Gnostic "Gospels" that contradict the Bible and have their origins in obvious demonic writings. Yet, some Christians have gotten offended with me for stating what should be common knowledge. Sadly, I believe many Christians are so blinded by their desire to discover “deep spiritual insights” that they neglect to “try/test the spirits” as we are told to do in 1 John 4:1. Or maybe their favorite teacher put forth some truth over the years that helped them, so they just accept their plausible possibilities and conjecture without REALLY looking at what the Scriptures plainly say. I have seen this scenario played out for decades on various subjects by various groups. When confronted with Scripture and given Biblical correction, often these teachers and/or their followers attempt to discredit or distract by claiming they are being "persecuted." But regardless of the emotional responses that arise, we cannot ignore ANY false teaching that subtly attacks the authority of Scripture or takes passages out of context. The 66 books of the Bible that God promised to preserve forever (Genesis to Malachi [39 books] and Matthew to Revelation [27 books]) are the Holy Spirit-inspired Word of God. No other writing is equal to the Bible, especially ancient demon-inspired books.

NOTHING NEW UNDER THE SUN

The Cain Serpent-Seed error is not a new “revelation” as some seem to think it is and it is certainly not new to me. This false belief has been put forth by certain Bible teachers for many decades. For instance, the misguided Pentecostal minister William Branham popularized this error during his ministry from 1945-1965. As a Pentecostal five-fold leader I have had to confront and correct followers of William Branham’s teachings over the years. In fact, I had a very intense debate in January of this year with a staunch Branhamite in a restaurant after he visited our church one Sunday. He brought up the Cain Serpent-Seed error and I responded with Scriptures. 

After first mentioning that I did not agree with the Cain Serpent-Seed error, I was accused of not considering the “Biblical evidence” for this doctrine due to “stubbornness.” It was assumed that I must not have spent time researching the subject. 

Here is a YouTube comment that I received after stating in a sermon that I disagreed with Zen Garcia about the Cain Serpent-Seed doctrine:
"With respect, I think you should at least address the SCRIPTURAL EVIDENCE (King James Version) which in my opinion outnumbers the evidence against. Genesis 4 is something that I have wondered about for some time now and I don't really know the answer. Here are the verses (plural) that you have to deal with if you're honest. Genesis 3:15, Isaiah 14:29, Isaiah 27:1, John 8:44-45. Also, I am not sure this is evidence, but I do think it is interesting that Cain is not listed in the genealogy of Adam in Genesis 5.  I really don't mean any disrespect, but I don't understand the stubborn refusal of some Christian pastors, or Christians in general of even listening or considering the Biblical evidence." 
Be careful what you wish for and be careful what you assume.  This pastor considered this doctrine decades ago and determined that it was error way back then. I just never took the time to address it in writing because quite frankly, I did not foresee so many Christians falling for it! Nevertheless, I will address the passages referred to by the YouTube critic and other proponents of this error.

THE REST OF THE STORY

Of course, the person who posted the above comment on my YouTube channel admits that Genesis four is a problem for their theory. They stated that they “…don't know the answer” to Genesis four. That means that they cannot come up with a way to change, explain away, or dodge the Genesis four “nail in the coffin” of this entire nonsense about Cain being the physical, genetic offspring of Satan from an alleged sexual encounter with Eve. And that brings me to my first point: 

***Genesis 4:1-2 establishes that ADAM had sex with Eve, she conceived and gave birth to Cain. Thus, any other idea, theory, or doctrine put forth about Cain's conception that contradicts this clear, literal, historical and Biblical truth is FALSE. Therefore, any further attempts to speculate, spiritualize, allegorize, postulate, infer, or squeeze some "proof" out of other Bible passages is an exercise in twisting/corrupting the pure, obvious teaching of the Word of God*** 

Some have stated that 2 Corinthians 11:1-4 proves that Eve lost her virginity to Satan.
“Would to God ye could bear with me a little in my folly: and indeed bear with me. For I am jealous over you with godly jealousy: for I have espoused you to one husband, that I may present you as a chaste virgin to Christ. But I fear, lest by any means, as the serpent beguiled Eve through his subtilty, so your minds should be corrupted from the simplicity that is in Christ. For if he that cometh preacheth another Jesus, whom we have not preached, or if ye receive another spirit, which ye have not received, or another gospel, which ye have not accepted, ye might well bear with him.”  (2 Corinthians 11:1-4)
This passage is clearly addressing the possibility of the MIND being corrupted. It is a comparison of the minds of the Corinthians being corrupted by a different message/gospel and the mind of Eve being corrupted by a different message/gospel (you will not die if you disobey God).  2 Corinthians 11 does NOT say or imply that Eve had sex with Satan and became pregnant with Cain. 

So once again, proponents of this error offer wild speculation that is adding to the Scripture and completely contradicting Genesis 4. If you are going to stay consistent with this interpretation of the Cain Serpent-Seed doctrine, then Paul’s warning to Christians in Corinth was about not having sex with Satan instead of the warning to not allow our minds to be corrupted/deceived like Eve’s. What I find absurd is how the Cain Serpent-Seed group will allegorize the fruit in Genesis 3 as being a metaphor for sex, but then take 2 Corinthians 11:1-4 as literal virginity being lost. Frankly, this false doctrine is a house of cards built upon wild speculation, bad hermeneutics, and the demonic influence of the Zohar and of the Gnostic heretics of the Gospel of Philip.

A REAL TREE WITH REAL FRUIT

There is no question that Eve’s mind was beguiled/deceived to eat the real fruit from a real tree in disobedience to God. How do we know it was real fruit from a real tree? God said it was…
“And the LORD God planted a garden eastward in Eden; and there he put the man whom he had formed. And out of the GROUND made the LORD God to grow every tree that is pleasant to the sight, and good for FOOD; the tree of life also IN THE MIDST OF THE GARDEN, and the tree of knowledge of good and evil. And a river went out of Eden to water the garden; and from thence it was parted, and became into four heads.” (Genesis 2:8-10)
And the LORD God commanded the man, saying, Of every tree of the garden thou mayest freely eat: But of the tree of the knowledge of good and evil, thou shalt not eat of it: for in the day that thou eatest thereof thou shalt surely die.” (Genesis 2:16-17)
God said He PLANTED a garden.
God said He made TREES to grow out of the GROUND.
God said EVERY TREE was pleasant to look at and good for FOOD.
God said these TREES were so real that He arranged for them to be watered by a river.
God said HE PUT the TREE Adam was not supposed to eat of in the MIDST (center) of the garden.


So those who believe the Cain Serpent-Seed error please answer these simple questions…

If Eve’s eating of fruit from the tree was actually her having sex with the Serpent/Satan...what grew out of the GROUND? Was it the Serpent or his penis?
If EVERY tree was pleasant to look at and good for food/fruit (which you say represents sex), did God give Adam and Eve permission to go about the garden having sex with other entities? He must have according to your theory because the garden was full of other trees they were allowed to “eat” from. 
Why did God need to water the Serpent/Satan?
Are you saying that when God put the tree of knowledge of good and evil in the center of the garden and said don’t eat from it, He actually put the Serpent/Satan in the center of the garden and say, “Don’t have sex with him?”


I believe if you study out the entire account of Adam and Eve without Cain Serpent-Seed colored glasses you will see how ludicrous the theory is.

THE REAL SERPENT SEED

So who is the real “serpent seed?” God said, "And I will put enmity between thee and the woman, and between thy seed and her seed; it shall bruise thy head, and thou shalt bruise his heel." (Genesis 3:15)

As I mentioned earlier, I do not deny there was and still is a genetic offspring of the fallen angels. They have been at war with God and His people for millennia and we are in the final stages of that battle. However, that seed or prodigy of the Serpent did not start with Eve and Cain. 

The Bible clearly tells us that Satan's seed in the earth started "...when men began to multiply on the face of the earth and daughters were born unto them, That the sons of God saw the daughters of men that they were fair: and they took them wives of all which they chose...There were giants in the earth in those days; and also after that, when the sons of God came in unto the daughters of men, and they bare [children] to them, the same [became] mighty men which [were] of old, men of renown" (Genesis 6:1-2, 4). 

The book of Job reveals that the angels were called "sons of God" under the Old Covenant. And that they shouted for joy as they watched the beginning of creation before God made mankind. Here is the account in Job 38:4-7:

"Where wast thou when I laid the foundations of the earth? declare, if thou hast understanding. Who hath laid the measures thereof, if thou knowest? or who hath stretched the line upon it? Whereupon are the foundations thereof fastened? or who laid the corner stone thereof; When the morning stars sang together, and all the SONS OF GOD shouted for joy?" 

As we read on in Scripture, we see entire clans that were genetic descendants of the giants who were from the seed of the fallen angels...

"And they brought up an evil report of the land which they had searched unto the children of Israel, saying, The land, through which we have gone to search it, [is] a land that eateth up the inhabitants thereof; and all the people that we saw in it [are] men of a great stature. And there we saw the giants, the sons of Anak, [which come] of the giants: and we were in our own sight as grasshoppers, and so we were in their sight" (Numbers 13:32-33).
"Whither shall we go up? our brethren have discouraged our heart, saying, The people [is] greater and taller than we; the cities [are] great and walled up to heaven; and moreover we have seen the sons of the Anakims there" (Deuteronomy 1:28).
"The Emims dwelt therein in times past, a people great, and many, and tall, as the Anakims; Which also were accounted giants, as the Anakims; but the Moabites call them Emims" (Deuteronomy 2:10-11).
"A people great and tall, the children of the Anakims, whom thou knowest, and [of whom] thou hast heard [say], Who can stand before the children of Anak!" (Deuteronomy 9:2). 
"And at that time came Joshua, and cut off the Anakims from the mountains, from Hebron, from Debir, from Anab, and from all the mountains of Judah, and from all the mountains of Israel: Joshua destroyed them utterly with their cities. There was none of the Anakims left in the land of the children of Israel: only in Gaza, in Gath, and in Ashdod, there remained" (Joshua 11:21-22). 
It is also clear in Scripture by God's instructions to Israel and His own actions in helping Edom against the ancient giants that the Lord wanted these giants destroyed. But like with Pharaoh and other evil attacks, God allowed them to test His people and their faith. This why the Creator YHVH, the God of Abraham ordered Israel to wipe out certain "people" groups...it was because they were not fully human. Even the book of Enoch (which many internet teachers/researchers fully accept because of it being quoted in the Bible) shows that God gave no hope or promise of redemption to the evil offspring of the fallen angels. 

The Nephilim and all the rest of their offspring were sentenced to eternal damnation, yet, we see in the Bible this exchange between God and Cain:
"And in process of time it came to pass, that Cain brought of the fruit of the ground an offering unto the LORD. And Abel, he also brought of the firstlings of his flock and of the fat thereof. And the LORD had respect unto Abel and to his offering: But unto Cain and to his offering he had not respect. And Cain was very wroth, and his countenance fell. And the LORD said unto Cain, Why art thou wroth? and why is thy countenance fallen? IF THOU DOEST WELL, SHALT THOU NOT BE ACCEPTED? and if thou doest not well, sin lieth at the door. And unto thee shall be his desire, and thou shalt rule over him" (Genesis 4:3-7).
The Lord told Cain that if he did well that he would be accepted. This should be a HUGE red flag about the Cain Serpent-Seed doctrine because that is not something the Lord EVER said or promised to the descendants of the fallen angels. Those evil half-breeds are reserved for destruction and damnation. Cain had a choice to give in to sin or not. His choice to give in to anger, jealousy, and the voice of Satan in his head didn't have anything to do with Cain being the genetic seed of the Serpent. Instead, it had everything to do with his own free will as a human man. He had a choice to yield to the voice of God or the voice of Satan and Cain chose the wrong one (just as his fully human mother did). 

The truths in Genesis chapters 4 and 6, negate the application of Genesis 3:15, John 8:44, 1 John 3:12 or any other passage being used as a "proof text" that Cain was the genetic seed of the Serpent. When Jesus debated the Pharisees in John 8, Jesus said this,"I KNOW THAT YE ARE ABRAHAM'S SEED; but ye seek to kill me, because my word hath no place in you" (John 8:37). So, the Lord Jesus was NOT teaching or implying that the Pharisees were the actual genetic seed of Satan when He said, "Ye are of [your] father the devil, and the lusts of your father ye will do. He was a murderer from the beginning, and abode not in the truth, because there is no truth in him. When he speaketh a lie, he speaketh of his own: for he is a liar, and the father of it" in John 8:44. Do you see that? Jesus acknowledged that the Pharisees were physical descendants of Abraham before He said they were of their “…father the devil.” This clearly shows that these leaders of Israel chose to be children of the devil through their actions just like Cain chose to give into the sins of jealousy, hatred, and murder to be “…of that wicked one.” (1 John 3:12). We all have this choice to make and it has absolutely nothing to do with being the physical seed of the Serpent/Satan.

The same principle applies to the rest of the verses mentioned from Isaiah as “evidence” of Cain being the Serpent-Seed. In context, do they implicate Cain as the genetic offspring of Satan? Not in the least! For example, look at Isaiah 14:29, “Rejoice not thou, whole Palestina, because the rod of him that smote thee is broken: for out of the serpent's root shall come forth a cockatrice, and his fruit [shall be] a fiery flying serpent.” Though this verse may vaguely refer to Satan’s fruit or seed, it DOES NOT mention Cain and thus you take a giant leap (aka assumption) to say it applies to him.  Once again, the fallen angel's "fruit" is clearly explained in Genesis 6:4.

As for Isaiah 27:1, I have heard the Cain Serpent-Seed group say that "piercing serpent" means the Serpent had sex with Eve. That is also quite a leap of speculation since neither Eve nor Cain are referred to in this verse or even in the chapter. “In that day the LORD with his sore and great and strong sword shall punish leviathan the piercing serpent, even leviathan that crooked serpent; and he shall slay the dragon that [is] in the sea.” 

Hopefully by now you can see that using this verse to teach that Cain is the physical offspring of Satan is beyond a stretch. And if you look up the word "piercing" in the Hebrew lexicon, it does not at all mean anything sexual. The Strong's Hebrew Dictionary defines piercing in this verse: bârîyach, baw-ree'-akh; or bâriach; (shortened) from H1272; a fugitive, i.e. the serpent (as fleeing), and the constellation by that name: —crooked, noble, piercing.”

CONCLUSION

In conclusion, it is painfully clear that the Cain Serpent-Seed doctrine is not at all Biblical and should not be taught or believed by any Christian or anyone for that matter. There are far more pressing and important matters that we should be spending our time on. This issue is truly a distraction and poses a more serious problem for Christians if they are led to believe they can and should allegorize or spiritualize any part of the Bible when they wish as the Jewish occult Zohar teaches. We must stick to solid principles of hermeneutics (Bible interpretation) and stay true to the Canon of Scripture when establishing sound Bible doctrine. Even when doing research, a Christian should ALWAYS take everything back to the Bible and throw out any sources that contradict God’s written Word.
“God forbid: yea, let God be true, but every man a liar; as it is written, That thou mightest be justified in thy sayings, and mightest overcome when thou art judged.” (Romans 3:4)