But love your enemies and be kind and do good [doing favors so that someone derives benefit from them] and lend, expecting and hoping for nothing in return but considering nothing as lost and despairing of no one; and then your recompense (your reward) will be great (rich, strong, intense, and abundant). - Luke 6:35
Has God ever asked you to do something really special for somebody who hurt you? If so, I am sure that like me you found it very difficult to do. Perhaps you have spent a lot of time in your life blessing someone who never blesses you in return. In that case, don’t become bitter but trust God to reward you.
Some of us are a little more naturally disposed toward kindness than others. Many of us find we can be kind to those who are kind to us, but we run into trouble with those we don’t think deserve kindness. God delights in being kind to those of us who don’t deserve it. Actually, kindness isn’t even kindness unless it is extended toward the undeserving.