- (Premise) There are no gratuitous evils.
- (Premise) If there is no God, some evils are gratuitous.
- Therefore, there is a God.
Here is a hypothesis. For some (a few? many? I have no idea) atheists, the conviction that there are gratuitous evils is a consequence of, not reason for, atheism. There is the natural intuition that there is a reason for everything, but a belief in atheism is rationally incompatible with that intuition, so the intuition is abandoned.