Why does Buddhism think that evil deeds are rewarded?

Buddhism advocates the causal cycle and warns the world that bad things will be rewarded in the end, which is a psychological hint of believing in Buddhism. China people have an idea that they are not afraid of what they see, but what they can't see. So when you get old, you will know that those who swear to heaven are actually taking advantage of people's fear of the future. Once a person has this kind of psychological suggestion, it is easy to blame any misfortune in life on his own evil. On the other hand, considering that the perpetrator is guilty, he will naturally be punished by morality, society and even law, which is naturally his retribution.