The life and trials of a growing Christian - Day One Hundred Sixteen

I really can't understand how somebody who claims to know or have known Jesus could just walk away from Him. I talked on facebook tonight to somebody who said that he was raised in a Christian home and would defend and share his faith anytime he could. That is until he started thinking in a "self-directed way." So he just up and quit on Jesus. He said that he "suddenly had the will to abandon any belief, no matter how dear." It's as if there were a switch on him and it suddenly got flipped to the off position. So my question is; did he ever really have a faith in Jesus or did he just regurgitate what his parents taught him? He also said that if he realized that something was "morally unacceptable or unjustifiable logically it led to his unbelief." Again I wonder; who's morals are he using? His, his friends, or the worlds? The same can be asked about the logic he's applying. Who's logic? I asked him if he would be open to slowly and methodically reading the book of John and he said that he had slowly and methodically read the entire bible and that's what had led him to turn away from God.
I've debated (I use that term loosely) this guy before and he's really smart, way smarter and more educated than stupid ole me, and yet he can't seem to understand the word of God. I'm not saying that I know or understand the entire bible because I certainly don't, but I know that God created everything including man in six days and rested on the seventh. I know that the first two people were tricked by Satan (the serpent) into disobeying God which is why there is sin and death in the world. I know that Jesus the Christ is God's son and yet God also and that He was born of a virgin and lived a sinless life and died and was raised from death saving all who would repent and be baptized from death and hell.
All I can figure is that he thinks himself to be too smart to buy into God, Jesus and the bible.The bible says in 1Corinthians 2:20 Where is the wise? Where is the scribe? Where is the disputer of this age? Has not God made foolish the wisdom of this world? 21 For since, in the wisdom of God, the world through wisdom did not know God, it pleased God through the foolishness of the message preached to save those who believe. 22 For Jews request a sign, and Greeks seek after wisdom; 23 but we preach Christ crucified, to the Jews a stumbling block and to the Greeks foolishness, 24 but to those who are called, both Jews and Greeks, Christ the power of God and the wisdom of God. 25 Because the foolishness of God is wiser than men, and the weakness of God is stronger than men.
Jesus is the only way to salvation. That might sound foolish, far fetched, too easy, or just plain not possible but it is. I have put my life on it, and I wouldn't just do that for maybe or could be. I hope that the man I talked to and everyone like him would reopen their hearts to Jesus and trust in Him and not in their own wisdom and abilities.