It's very hard to do in some cases, but people who have Jesus can ask Him to help them to love the people who are difficult to love (and pray for the ones who are difficult to pray for), and He will. We need to pray for agape love (the kind of love God has), because due to our being human, we cannot achieve it on our own. 1 John 4:8 says that if you don't have love, you do not know God -- for God is love.
