"But I say to you, Love your enemies: do good to them that hate you: and pray for them that persecute and calumniate you" (Matthew 5:44). Our Lord Himself commands us to pray for those who do not believe, even when their unbelief leads them to hate us for our belief.
In this prayer for unbelievers, we are reminded that they, too, are the children of God, and that their conversion would only increase our joy.
A Prayer for Unbelievers
O God, the everlasting Creator of all things, remember that the souls of unbelievers were made by Thee and formed in Thine own image and likeness. Remember that Jesus, Thy Son, endured a most bitter death for their salvation. Permit not, I beseech Thee, O Lord, that Thy Son should be any longer despised by unbelievers, but do Thou graciously accept the prayers of holy men and of the Church, the Spouse of Thy most holy Son, and be mindful of Thy mercy. Forget their idolatry and unbelief, and grant that they too may some day know Him whom Thou hast sent, even the Lord Jesus Christ, who is our Salvation, our Life and Resurrection, by whom we have been saved and delivered, to whom be glory for endless ages. Amen.