“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 God can abolish evil, and God really wants to do it, why is there evil in the world?” — Epicurus
Early philosophers like Epicurus pondered over such problems and to this day his thoughts apply such that no theologian has been able to refute. Further reasons for disbelief comes from an argument which states that if God created the universe, then who created God. Religious people try to counter this with, “God doesn’t need a creator”. If that is so, why does the universe need a creator?
There are a few notions put forth by religious philosophers that have been taken seriously in the past, but will sound ridiculous to the modern human. One such case is the Ontological argument. It states that if you can conceive a all powerful creator, then that being can exist. This crumbles under many scenarios. Can the “Omnipotent” God create a rock that he cannot lift? Why do Christians say, “God cannot lie,” and so on.
Another argument for God that had even scientific minds believing in is Paley’s Watch. William Paley wrote that if you find a watch on a beach, you will instantly assume that somebody left it there and that it was not formed naturally. The modern equivalent to this would be “Irreducible Complexity” by Michael Behe which states that some body parts like the eye is so complex that it could not happen by “chance”. Darwin destroyed Paley’s assertion by introducing his own theory. Behe’s arguments fall short as Evolution by Natural Selection can explain how an eye forms.
One of my favourite religious defences is Pascal’s Wager. Pascal alleges that if there is no God and you follow the religious teachings you lose nothing but if there is a God and you follow the teachings you gain everything. There are two holes in this claim, one being that you do lose something, your time, money and freedom. The other is that even if there is a God which religion has got it right, or even if any of them have got it right.