The idea is that Adam sinned, and thereafter his sinfulness was passed down through his bloodline to all of humanity.
But let’s just think about this for a moment.
First, in order for this to be the case, the act of Adam’s sin would have had to somehow result in a change in his genetic make-up. So… Adam bites into the forbidden fruit, and his DNA – the core of his being, which God himself has declared “very good” – instantaneously transmutes into Very Bad DNA. How does that work? Magic?
Second, Adam’s Very Bad DNA™ is now passed on through his sperm to all of his children. How does this work? One wonders what other non-physical characteristics might unwittingly be passed on through bodily fluids. Perhaps I can blame my impatience, my penchant for sugary snacks, my habit of biting my fingernails – in fact, every one of my less than positive traits – on my parents? “Not my fault, Your Honour – it’s in my genes, you see!”
(Never mind the fact that this idea also requires an unswerving belief that Adam is the common ancestor of all humanity… But that’s another story.)
Also, if we all inherit the sin gene from our progenitors, why is it, then, that once a person is declared sin-free by God (the Apostle Paul uses the word “righteous”), their sin-free state is not similarly passed on to their children?
Sorry, Augustine – top marks for effort, but a fail overall.
[ Image: Shinichi Sugiyama ]