The fool has said in his heart, “There is no God.” They are corrupt, They have done abominable works, There is none who does good. - Psalm 14:1 NKJ
"IT IS PHILOSOPHICALLY IMPOSSIBLE to be an atheist, since to be an atheist you must have infinite knowledge in order to know absolutely that there is no God. But to have infinite knowledge, you would have to be God yourself. It's hard to be God yourself and an atheist at the same time!" (from Fast Facts on False Teachings by Ron Carlson and Ed Decker)
If the "fool" is finally willing to admit his need for God, here is a quick test to see if he meets God's standards for eternal life in heaven: http://www.needgod.com/