My daughter teaches Kindergarten. In this school, all Kindergartners report to the gym every morning and wait for the bell to ring. The teachers rotate duty supervising the students.
One morning when she had duty, a little boy walked in, looked at the little girl at the front of the line and said, "You can't be mean to me anymore because I went to church yesterday and I prayed. And Jesus is going to help me not be mad at you." Then promptly walked to the back of the line. A few minutes later, my daughter saw the little girl get up, walk to the back of the line and hug him.
If two five year olds can do this, why can't adults? “If you love those who love you, what credit is that to you? Even sinners love those who love them. Luke 6:26.
But love your enemies, do good to them, and lend to them without expecting to get anything back. Then your reward will be great, and you will be children of the Most High, because he is kind to the ungrateful and wicked. Luke 6:35.