Question: Genesis:3:15 mentions the serpent's seed and the seed of the woman, which was Jesus Christ. Does it not appear that if the serpent's seed wasn't real, that Jesus could not have been real?
Response: You are saying that if the "seed of the serpent" is not a literal seed, then how could the Lord Jesus be real as well? It sounds as though you support what is called the "Serpent Seed" doctrine, in which the sin of Eve was having sexual relations with the Serpent.
There is no biblical support for this heresy. The "serpent seed" doctrine is nothing new, having been a part of the teaching of William Branham in the earlier part of the last century. Other false teachers have taught the same, probably going back to the very early church. After all, Paul warned that, "...after my departing shall grievous wolves enter in among you, not sparing the flock. Also of your own selves shall men arise, speaking perverse things, to draw away disciples after them." (Acts:20:29-30). As Jeremiah records in 17:9, "The heart is deceitful above all things, and desperately wicked: who can know it?" Here is where prayer comes in, for the very next verse states, "I the LORD search the heart, I try the reins..." (Jer:17:10).
Who, then, is the Lord talking about in the Genesis:3:15 prophecy? In truth, those who would "bruise his heel" were those who would follow Satan. The Lord Jesus rebuked the Pharisees, "Ye are of your father the devil, and the lusts of your father ye will do" (John:8:44). Can anyone imagine that Jesus is saying that the Pharisees were the literal physical seed of Satan?
During the flood of Noah, "every living substance was destroyed which was upon the face of the ground, both man, and cattle, and the creeping things, and the fowl of the heaven; and they were destroyed from the earth: and Noah only remained alive, and they that were with him in the ark" (Gn 7:23). That "living substance" that was destroyed included every descendant of Cain, who, according to this teaching, was fathered by the Serpent.
Genesis:4:1 tells us that "Adam knew Eve his wife; and she conceived, and bare Cain...." It wasn't until Adam had relations with his wife that she conceived. Any other idea must be willfully forced upon Scripture. Consequently, how can anyone conclude that the "seed of the serpent" in Genesis 3 is talking about more than those who would follow Satan and reject the Lord? We cannot, without departing from Scripture.