The problem of Evil
Before Christ was born there was a Greek by the name of Epicurus (born in 341 BC) who was the first person to recorded to describe the problem of an omnipotent, benevolent God and at the same time there to be evil in the world.
A quote of his on the subject:
"Either God wants to abolish evil, and cannot; or he can, but does not want to. ... If he wants to, but cannot, he is impotent. If he can, but does not want to, he is wicked. ... If, as they say, God can abolish evil, and God really wants to do it, why is there evil in the world?"
I remeber long ago reading about why before Christianity that no religion wanted to claim that their God was all powerful and cared anything about the world because of the problem of evil would make the religion not rational to others.
Since it's been around forever Christian scholars have created several agruements as to how an omnipotent God and evil can exist at the same time, however none of them can explain away this problem.
It is kinda funny that an athesist arguement that was created even before Christianity would still be to this day one of the biggest reasons as to why someone would not believe in God.
Feel free to post your thoughts on the subject..