Romans 12:14

Bless them which persecute you - Ευλογειτε, Give good words, or pray for them that give you bad words, καταρασθε, who make dire imprecations against you. Bless them, pray for them, and on no account curse them, whatever the provocation may be. Have the loving, forgiving mind that was in your Lord.

Bless them ... - see the note at Matthew 5:44; compare Luke 6:28.

Bless, and curse not - Bless only; or continue to bless, however long or aggravated may be the injury. Do not be provoked to anger, or to cursing, by any injury, persecution, or reviling. This is one of the most severe and difficult duties of the Christian religion; and it is a duty which nothing else but religion will enable people to perform. To curse denotes properly to devote to destruction. Where there is power to do it, it implies the destruction of the object. Thus, the fig-tree that was cursed by the Saviour soon withered away: Mark 11:21. Thus, those whom God curses will be certainly destroyed; Matthew 25:41. Where there is not power to do it, to curse implies the invoking of the aid of God to devote to destruction. Hence, it means to imprecate; to implore a curse from God to rest on others; to pray that God would destroy them. In a larger sense still, it means to abuse by reproachful words; to calumniate; or to express oneself in a violent, profane, and outrageous manner. In this passage it seems to have special reference to this.

12:14 Curse not - No, not in your heart.