Pray that they come to know the Lord. Never pray ill for anyone. If you do, you may find yourself receiving what you pray for them.

That's right , Rom12 20
How many times in the Bible is being tried by fire mentioned?
Removing impurities from precious metals such as gold and silver?
The next vs is ROM 12. 21 Be not overcome of evil, but overcome evil with good.
We were all created in God's image, even our enemy's.
Some times they just need to see some goodness to help remove a little droth.

Now HT, there was a pastor of the colonial era that prayed for their enemies. Seems a band of pirates had raided and robbed the village in which he ministered. He called all the men of the church together and they prayed all throughout the night that those pirates would come to understand that they had done wrong and turn themselves in. Well come morning no pirates had showed so those men that had prayed for them formed a posse, captured those pirates, and promptly hung them. Read this story when researching the Black Robbed Regiment.

It seems God always instructs for us to do what isn't easy. Why would he ask us to do what we already do anyway?
The Word of God - recorded as God's own words by Matthew (5:43-46) - answers your question HT. No need for too much commentary except that our prayer should be that God would aid us in doing what we don't prefer to do (I know I can be a Jonah too often);

“You have heard that it was said, ‘YOU SHALL LOVE YOUR NEIGHBOR and hate your enemy. But I say to you, love your enemies and pray for those who persecute you, so that you may be sons of your Father who is in heaven; for He causes His sun to rise on the evil and the good, and sends rain on the righteous and the unrighteous. For if you love those who love you, what reward do you have? Do not even the tax collectors do the same? If you greet only your brothers, what more are you doing than others? Do not even the Gentiles do the same? Therefore you are to be perfect, as your heavenly Father is perfect."

Aren't we immeasurably blessed that God doesn't hate those who hate Him cause that is/was all of us. Simply put, God sent His Son to show us how to love the One we hate.

Blessings,
Mark