Love is a spirit. When we fall in love we are connected to God for God is love 1 John 4:8. God has made us according to His image and likeness, Genesis 1:26, we are small Gods. Since God is love we are love. Our spirit is love.
Hate is the absence of love. How can we hate if we are like God, we are love? When we think solely of ourselves that is when we are selfish we can hate. Selfishness leads to hate. A selfish person can be defined as a person who loves greatly himself. When we insult such a person the idea of himself as great is distorted and he hates us. A selfish person puts himself above all since he loves himself. How can such a person be healed?
Firstly, let me tell you that a selfish person protects himself. A gorgeous woman who sees the mirror loves herself and forms a high opinion of herself, she becomes selfish. This selfishness is the cause for rejecting men, for being careful not to fall in love. When a handsome great man approaches then she gives in getting to know him better and why not fall in love with him.
I think part of selfishness is in the genes you are born with it and and it is the root for many troubles. We can heal a selfish person if we pray for him. He starts loving God and other people and the love of himself is displaced.