One reason why I don't believe in God is that I don't think there's any need for a God. Many people look at the universe, human beings, and other complex things and think that these couldn't have come into being without a God. But to me, this just substitutes one mystery for another. The question then becomes: where did God come from? Such a powerful creator would itself call for an explanation as to why it exists. Because of this, I end up concluding that not everything has to have a cause--that even complicated things can exist on their own without a creator.

Often, people point to positive things--people with illnesses recovering or improving, people being motivated to be medical researchers or help others in other ways--as being evidence of God's power at work. But if God (at least an all powerful God) is going to be credited with the amazingly good things that take place, wouldn't he ("it" might be a better pronoun) also have to be blamed for the bad things as well--for example, for making Hitler want to do what he did, and for all the horrible diseases that exist?

In addition, even if there is a God, I don't see a clear reason why God would be morally good. As human history makes abundantly clear, power doesn't equal goodness.