In a previous article I have argued that we do not inherit a sinful nature from Adam, but rather the sinful nature a person has comes from their own wicked choices in the past. Also, many people confuse their own demonic oppression with some kind of sinful nature. They think what demons are saying are their own thoughts, so they conclude that they have a sinful nature and were “born that way”. Thankfully, in Christ, all things become new (2 Corinthians 5:17), we can become free indeed (John 8:31-34) and we can crucify the flesh with its passions and desires (Galatians 5:24). This doesn’t mean that demons never tempt us to fulfil natural desires in unlawful ways. They will do this until we get to heaven, but usually with less intensity as we grow in sanctification. The overwhelming testimony of the New Testament is that in Christ we can overcome the world, the flesh and the devil – even if we have to suffer greatly in our struggle against sin.

But Augustine of Hippo, a bishop from North Africa, so greatly influenced both Roman Catholic and Protestant theology, that many people unquestioningly accept any theological statement simply on the basis that Augustine said it. 

‘Augustine himself. (A wonderful saint! As full of pride, passion, bitterness, censoriousness, and as foul-mouthed to all that contradicted him… When Augustine’s passions were heated, his word is not worth a rush. And here is the secret: St. Augustine was angry at Pelagius: Hence he slandered and abused him, (as his manner was), without either fear or shame. And St. Augustine was then in the Christian world, what Aristotle was afterwards: There needed no other proof of any assertion, than Ipse dixit: “St. Augustine said it.” ‘
– John Wesley, The Works of the Late Reverend John Wesley (1835 Edition), volume 2, p. 110

To get an idea of how much Augustine may have been philosophically influenced by Gnostic ideas , see this page. You will learn that a lot of currently accepted theology has a lot in common with Gnosticism, which believed that man’s flesh was basically evil. Gnostics said the body was evil because it was made by an inferior god, the demiurge. For gnostics, salvation was by knowing certain ideas. It didn’t matter how you lived. Augustine said the body was evil because Adam’s sinfulness was passed down through sex. For Augustine, salvation was by an unconditional election or predestination and if you were elect, it didn’t really matter how you lived, or that you went on sinning. You were secure because you held the right doctrine. You had the right intellectual/spiritual knowledge. You can see that Gnosticism and Augustinianism, although different, have plenty of similarities. Many of these ideas were explicitly opposed by the Ante-Nicene “Church Fathers” – that is the Christian leaders who lived before AD 300, many of whom knew the apostles or people the apostles had taught personally.

Does Sin Come to Us Through Sex?

Augustine had a big hang up about sex. Perhaps it was because before his conversion he played around in Carthage, and was infatuated with a mistress he had for 14 years. Apparently, he was a sexually immoral man. But just because sex can easily be abused does not mean that the pleasure of fulfilled desire in sexual intercourse within marriage is something inherently sinful. Augustine, however, taught that it was. 

According to Augustine, the reason that Jesus Christ, born of Mary, did not have a “sinful nature” is because no sexual intercourse was involved in the conception of Jesus. That might sound reasonable, and many at the time believed it, but it doesn’t make it right. According to the Bible

Marriage is honorable among all, and the bed undefiled; but fornicators and adulterers God will judge. (Hebrews 13:4)

If Augustine is right, lustful pleasure in sexual intercourse in marriage is sinful. But why does God say that the marriage bed is undefiled? 

Augustine had to come up with something like this, because he also had a theory that the sinful nature was passed down from parent to child. This is one reason why the Roman Catholic church – and Augustine was a Roman Catholic – has made much about the alleged sinlessness of Mary. They had to explain how Jesus was not sinful. To explain how Mary was not sinful, they also had to invent the idea that Mary’s parents also were not sinful. Why they didn’t feel the need to take this all the way back to Adam to prove that all the generations in the past were not sinful, I cannot say now. To me the whole theological system here is faulty. 

Augustine tried to use Psalm 51:5 to prove that it was the act of conception through sexual intercourse that made David sinful.

Behold, I was brought forth in iniquity,
And in sin my mother conceived me. (Psalm 51:5)

A few things should be said about this. Firstly, even if it applied to David, it doesn’t mean that all mothers conceived their children in sin. Quite possibly, David was illegitimate, which is why he wasn’t even brought before the prophet Samuel for consideration when at first Jesse presented his sons to the prophet. It seems that David had half sisters, Zeruiah and Abigail, who the Bible records were daughters of Nahash the Ammonite (1 Chronicles 2:13-16). But the father of at least one of them was Nahash the Ammonite according to 2 Samuel 17:25. I think all David is saying in this passage was that sexual sin was involved in the circumstances around his conception. Perhaps for this reason there was this generational iniquity around lust and a weakness for women which David had – and so did Solomon and Rehoboam. But even if David had this weakness, it didn’t excuse the sin, and it doesn’t mean that every person who ever lived apart from the Lord Jesus Christ was conceived by a sinful act of sexual intercourse. So Augustine is going way beyond Scripture when he uses this passage to try to prove that all sex transmits inherent sinfulness.

For more on Augustine, I recommend you take a look at this article which ties elements Gnosticism to Augustine’s thinking. It is also worth looking at lawyer David Bercot’s book, available on Amazon, “Will the Real Heretics Please Stand Up”.