St. Worm2 said:
Ephesians 2:2-3 seems clear enough when it calls us "sons of disobedience" and then tells us that we "were by nature (IOW, born), children of wrath, even as the rest". Sin is a problem of the will to be sure, but that only because our wills are incapable of completely resisting our nature! We sin BECAUSE we are sinners, not the other way around.
So the real question is, "how did we get this way"!! If God made Adam with a sin nature (and so, through him genetically, the rest of humanity as well), how can we held accountable for sinning? Likewise, if the cause was not a result of the Fall, we are left in the same boat (or, rather, God is). IOW, if Adam is not the cause of humanity's universally depraved nature, then God must be (in that He would have had to MAKE us this way), thus making Him, the Author of sin.
Post Tenebras Lux,
David