In the Bible, this is one of the most difficult and counter-cultural commands. The world was saved by Jesus while we were His enemies. However, the context is essential. There will be judgment for those who are praised by the world because they say what the world wants to hear. Here, the enemies are those who hate those who love Christ. Likewise, this command is intended to focus on seeking the good of the other person rather than enabling, endorsing, or cooperating in their abuse.
In the Christian's arsenal, the supernatural love of God is an incredible weapon. The only one who is indwelt by the Holy Spirit can wield this weapon of war. Only through the love of Christ that is manifest in our hearts will we be able to love our enemies, to do good to those who hate us, to pray for those who despitefully use us, and to return kindness to those who mock us and ridicule us, hate us and kill us.
Godly love is one that is beyond the nature and understanding of unregenerate people. By ourselves, we will never be able to love our enemies and do good for those who are unkind to us and spitefully use us. Godly love cannot be learned through education or developed through training. It is from a heart that places Christ at the center of every aspect of their lives that God's divine love flows.

Dear Heavenly Father, thank You for giving me a new nature through faith in Christ. Throughout my life, I pray that I will become more like the Lord Jesus in the choices I make. Father, I know that in my own strength, I can never love those who hate and despise me, but I pray that through Your grace, You would guide my decisions so that they align with Your perfect will so that others can experience Your love through me. 
In Jesus's name I pray. Amen.