Yea. Any religion that believes in a just interving diety runs into this.
If i really believe my god is perfect and all powerful, then why should I have compassion for all the unlucky people that god clearly despises?
It's hard, because the idea of a perfect loving god is incredibly attractive.
It's the evidence that sucks: if god is real and all powerful, then god is, at best ineffable, and at worst a terrible raging asshole who lovingly created a parasite that eats childrens eyes.
Now, if we're willing to believe in a sort of weak impotent god, the theology gets more interesting.
I wish I could upvote this twice! I'm actually on my way around to my second re-read of "Small Gods" during another full Discworld read-through.