Why do people put you down to make themselves feel better?

I think they do this in order for them to feel better about theirselves. I currently have a situation going on to where me and this other person do not even talk anymore because he was always putting me down when we do talk. He blames him not doing something because I have not done it. And that I am a lazy bla, bla, bla. But yet I am not able to do some of the things and so on. But yet he still makes me out to be the bad guy so to speak just so he can feel better about being such a louse. I know that in the future that after this person is a little bit happier then he will learn to be nice or he will never have anyone to love.