This paper discusses the rational proofs of God’s reality and other philosophical arguments.
An even more interesting part about the scriptural evidence is the verses that specifically address issues of believing (or lack thereof)! For example, 1 Cor. 2:14 explains, The man without the Spirit does not accept the things that come from the Spirit of God, for they are foolishness to him, and he cannot understand them, because they are spiritually discerned. This verse basically acknowledges the fact that it is difficult for man to believe in something he cannot see or touch.