In God’s creation there are all sort of things. He has created bad men as well as good men. It is He who gives us good tendencies, and it is He again who gives us evil tendencies. Sin begets its own result. This is God’s law.
Won’t you burn your tongue if you chew a chili? So one should be careful about anger, passion, and greed. Take for instance, the case of Hanuman in Ramayana. In a fit of anger he burnt Ceylon. At last he remembered that Sita was living in Asoka grove. Then he began to tremble lest the fire should injure her.