When I do good, I earn the merit. Allah says the reward will be good in this world and the next. If you do wrong, you suffer spiritually. Doubt stresses a person, lovelessness stresses a person and suspicion is troubling. You try to take revenge but end up being horribly troubled. But if you are pleasant natured, your nerves all relax, your brain relaxes. Then you can be joyful. Allah says that doing evil will suffocate you. - Harun Yahya