The Fifth Commandment: “You Shall Not Kill”
Hatred is a sin that kills the heart. It destroys innocence. It is un-Christian simply because as Christians we are all called to be Christ-like. Christ does not hate anyone, but He loves us all.
Jesus mentions in both the Gospels of Matthew and Mark, that we are called to love as He does. When Jesus is asked which of all the Commandments is the greatest, we read in Matthew:
Master, which is the greatest commandment in the law? Jesus said to him: Thou shalt love the Lord thy God with thy whole heart, and with thy whole soul, and with thy whole mind. This is the greatest and the first commandment. And the second is like to this: Thou shalt love thy neighbour as thyself.  On these two commandments dependeth the whole law and the prophets. Matthew 22:36-39
Similarly,we read in Mark:
And there came one of the scribes that had heard them reasoning together, and seeing that he had answered them well, asked him which was the first commandment of all. And Jesus answered him: The first commandment of all is, Hear, O Israel: the Lord thy God is one God. And thou shalt love the Lord thy God, with thy whole heart, and with thy whole soul, and with thy whole mind, and with thy whole strength. This is the first commandment. And the second is like to it: Thou shalt love thy neighbour as thyself. There is no other commandment greater than these. Mark 12:28-31
Jesus makes it crystal clear. We are to love one another as He has loved us. We are to love our enemies and pray for them!
Hate is the absence of love. And the absence of love is the absence of Christ. And the absence of Christ is the complete removal and disconnect from the state of grace.
There are people who upset us and the devil uses this as opportunities to tempt us into giving into hatred. Being upset with someone is not the same as hating them. Being upset with someone is a perfectly normal reaction, especially when someone does something sinful and should know better.
Bigotry is a sin because you hate someone for something that they are. What makes bigotry worse than hatred is that it is hatred specifically because of something that they are.
It is never right to hate anybody. No matter what they have done. If you are going to hate anything, hate sin. Hate sin so much that you avoid it any time it rears its ugly head. Sin destroys everything and ruins your relationship with God. Sin makes us worthy of that eternal punishment below.
If you are struggling with anger, take it to confession. God hates your sin, but He doesn’t hate you. Likewise, hate sin and not each other. The same way that Christ forgives your sin in the confessional, forgive others what they have done to you. Make amends, talk with them and depending on the situation, continue having them in your lives. If this is not a possibility and having them in your life continues pain and anger, keep them away until you have healed.
Love one another as Christ loves you. Forgive others of their trespasses, as God forgives you of your trespasses.