The world is made of good and evil people. There are some, who are nothing but emperors of evilness. Hitler was one such person. There are many like him. But we also have evil persons in our society who are generally not considered evil, but are evil. Let me give my thoughts on such people.
For me, a person who hits a stray dog with a stone just for fun is a bad person. One who gives pains to friends for no reason is a bad person. One who looks at wrong things, and decides to do nothing is evil. One who hurts feelings of loved ones is a bad person. One who lets other people sleep in hunger without doing anything about them is a bad person. One who wants bigger share of the pie is a bad person. One who shouts and makes others fear him/her is a bad person. One who never tries to understand feelings of others is a bad person. One who treats poor people as dirt, is a bad person. One who decides about characters by looks and passes judgments is a bad person. One who reads a sad story in the newspaper, without getting affected in any way is a bad person. One who shows no respect for those who work for others is a bad person. One who does not sympathize at others losses is a bad person. One who always tries to prove his/her superiority over others is a bad person. On and on I can write. What is not good is bad. That is how I call such people bad. Rather than calling them as not good persons, I call them as bad persons. All this may look quite shocking and many will protest about what all I have written above. All right, let me say, that I will not call the person a bad person, but the act as a bad act. I hope that now I am more acceptable.
Then, what is evil? Evilness is a quality in a person, whereby that person hurts others in ways that the very life is taken away. One need not kill with a sword to be called evil. At times, making false allegations on someone who never did what he/she is being blamed with is enough to kill the spirit and the body. That act is evil, and the person who acts like that is evil.