Is God willing to prevent evil, but not able? Then he is not omnipotent. Is he able, but not willing? Then he is malevolent. Is he both able and willing? Then whence cometh evil? Is he neither able nor willing? Then why call him God? - Epicurus (Paraphrased and disputed, yet widely attributed to.)
I've always loved that quote, whoever it came from.
Both sides of a sports match pray to god that they win. One team scores more points, and wins. Does god prefer that team? No, god doesn't exist. But if he did exist, and did intervene to make one team win, he's petty.
A very young European child with bone cancer and a very young African child with bone cancer pray to god that they survive. The European child with superior medical services survives, while the African child dies. Is god a shithead immoral asshole? No, god doesn't exist. If he did exist and did choose one child over the other, he's a shithead immoral asshole.
Is God willing to prevent evil, but not able? Then he is not omnipotent. Is he able, but not willing? Then he is malevolent. Is he both able and willing? Then whence cometh evil? Is he neither able nor willing? Then why call him God?