Jan, if we cannot know when Sin first occurred and how, how can any religion claim we are " all sinners" and " born in sin" ?? I think both of those statements are WRONG. But then, I am not a Bible believer, I would very much like someone with real Bible knowledge, not a JW or other Bible literalist, explain from Scripture, as you say, the " mechanics" of it. Obviously Paul's writings don't count, he had his own ideas on Sin and whence it came, but they make no sense if the Adam and Eve story is just a metaphor, as it surely is.
If there is no " Sin" then Jesus died for what ?
And if like the Apostle Paul, you believe Jesus was resurrected to life in Heaven, of what significance is this ?