One cannot simply throw out the concept of the serpent's seed! Passages like that above, 'You are of your father the devil, and the desires of your father you want to do' ( from John 8:44 ) & 'not as Cain who was of the wicked one and murdered his brother' ( I John 3:12 ) are pretty clear that there were those who were descended, in a spiritual sense, from this 'serpent', 'devil' or 'wicked one'! The question before us, barely even a consideration, it seems preposterous, is whether there was actually a third person, a spirit being called 'Satan', who took the form of a 'serpent' in the Story in question!
The website of which I speak ( found HERE-EAYOR ), and like I say, there are some good points made by the author, is based upon the same presupposition that 'the sons of God' of Genesis 6 & Job 1 were angelic, or spirit beings, and not simply human messengers. The whole notion of spirit beings impregnating human beings, you might well say, is so preposterous that it is hardly even worth treating! The traditional belief,, though, among Christians, we understand, is that the Holy Spirit impregnated the Virgin Mary! If this occurred as & how we traditionally posit, why is it so hard for us to believe that 'the sons of God' were who most Christians say they were? ( I'm not saying that they were )
If 'the serpent' was actually this 'Satan' ( a spirit being ) in some other form, then we might well posit that the promises of God WERE according to physical ( or some hybrid thereof ) descent! If, however, 'the serpent' was simply another man who introduced doubt into the mind of his bestial lover that God was a force to be reckoned with, we can easily understand how his resulting seed might be at enmity with Adam's spiritual lineage in continuity!
The Covenant Creation model, or understanding not only makes sense of some of the questions that have arisen from the traditional understanding of the creation accounts in Genesis 1 & 2, it also makes sense out of the Story related in Genesis 3! As Adam was not the first human being on planet earth, so the 'sons of God' were not literally begotten of God, but spiritually, just as Timothy was the apostle Paul's 'son' ( I Corinthians 4:17 ); we are 'sons of God', not through physical, but spiritual generation! Only if we look at this Story through Covenant Creation Eyes does it make sense, and not call for dangerous speculation as some have become embroiled in through the traditional & futurist understanding!
To understand the 'serpent's seed' as by spiritual generation, as to understand 'the sons of God' by spiritual generation is really the only way to understand this concept; any other way involves vain speculation & useless wrangling! To try to bring the focus to bear simply on the physical aspect of generation is to say that it is our physical descent that determines our spiritual standing. If such is the Truth, then we today truly have no hope at all, and we are of all men most miserable!
Charles Haddon Shank