"You have heard that it was said, ‘You shall love your neighbor and hate your enemy.' But I say to you, love your enemies, bless those who curse you, do good to those who hate you, and pray for those who spitefully use you and persecute you, that you may be sons of your Father in heaven; for He makes His sun rise on the evil and on the good, and sends rain on the just and on the unjust'" (Matthew 5:43-45).
These are not suggestions to be considered, they are commands to be obeyed. "A pretty tall order," you say. Perhaps, but definitely within the realm of possibility.
Jesus would never tell us to do something we could not do. That would be unjust. We can bless, we can do good, we can pray for and forgive those who have wronged us.
When people say, "I can't forgive," that generally means, "I won't forgive." The ability to love, bless and forgive is within us—because God is within us. Learn to let His nature of love dominate you. Choose to love. Let what God has put on the inside come out.
The world needs to see real love—the kind of unconditional love that brought us into God's family. And they need to see it in us. If we really are the children of God, then His nature should be displayed in us and through us. The most outstanding feature of God's nature is love. God is love.
One last thing. When you choose to love and forgive those who have wronged you, you set a prisoner free. The prisoner is you.