For me, it was a high school class on the Pentateuch. After we studied the Torah, I realized that Christianity simple could not be rationalized against what it said.<quoted text>
Pretty much sums it up. For me the breaking point was when I read Josh McDowell's "Evidence that Demands a Verdict". I realized that this was not even good circumstantial evidence. It is pure rationalization. Since I was a fundie at the time it was pretty much like being hit in the gut. But here is the thing. If I had not seen it for myself I do not think anyone could have convinced me.
And I should have remembered that before I posted it...Actually the Tao te Ching makes no claim for itself and Buddha actually told his disciples, in no uncertain terms, that what he taught should be investigated deeply and with skepticism. And if it was found to not be true then one should reject it.
OTOH neither Taoism nor Buddhism claim divine inspiration or even literal truth. Siddhartha reminded people many times that his words were like a finger pointing at the moon and one could not misunderstand worse than to think the words themselves were the point.
LOL.As for myself I have come full circle and once again affix the label "Christian" to myself abet with a twinge of desire to put an asterisk after it. But my views as a Christian are profoundly different than they were in my fundy youth. Now I am just a simple Buddhist/taoist/gnostic/deisti c-Christian.