Prayers for Enemies

Troparian
Thou Who didst pray for them that crucified Thee, O Lord, Lover of the souls of men, and Who didst command Thy servants to pray for their enemies, forgive those who hate and maltreat us, and turn our lives from all harm and evil to brotherly love and good works. For this we humbly bring our prayer, that with one accord and one heart we may glorify Thee Who alone lovest man.

Kontakion
As Thy first martyr Stephen prayed to Thee for his murderers, O Lord, so we fall before Thee and pray: Forgive all who hate and maltreat us, and let not one of them perish because of us, but may all be saved by Thy grace, O God the all-bountiful.

Also … check out the beautiful prayer by St Nicolai of Zica.