Believers say that God is perfectly good, and that he's all-powerful. They also say he created the whole world and everything in it. But the world is filled with evil. Everywhere you look there's violence, corruption, injustice, poverty, starvation, and disease. If there really were a perfectly good and all-powerful God who created everything, how could he allow the world to go so bad? If he were perfectly good then he wouldn't want evil to exist, right? And if he were all-powerful then he could prevent evil from existing, right? So either he's not perfectly good, or he's not all-powerful, or...