But I say unto you, That whosoever is angry with his brother without a cause shall be in danger of the judgment: and whosoever shall say to his brother, Raca, shall be in danger of the council: but whosoever shall say, Thou fool, shall be in danger of hell fire. Matthew 5:22
Through Moses the Lord had said, "Thou shalt not hate thy brother in thine heart....Thou shalt not avenge, nor bear any grudge against the children of thy people, but thou shalt love thy neighbor as thyself" (Leviticus 19:17, 18). The truths which Christ presented were the same that had been taught by the prophets, but they had become obscured through hardness of heart and love of sin....
The spirit of hatred and revenge originated with Satan, and it led him to put to death the Son of God. Whoever cherishes malice or unkindness is cherishing he same spirit, and its fruit will be unto death. In the revengeful thought the evil deed lies enfolded, as the plant in the seed. "Whosoever hateth his brother is a murderer: and ye know that no murderer hath eternal life abiding in him" (1 John 3:15). (Thoughts from the Mount of Blessing, 55, 56)
Reflection: His example is for us. When we are brought in conflict with the enemies of Christ, we should say nothing in a spirit of retaliation or that would bear even the appearance of a railing accusation. He who stands as a mouthpiece for God should not utter words which even the Majesty of heaven would not use when contending with Satan. We are to leave with God the work of judging and condemning (Thoughts from the Mount of Blessing, 57). Today, let's ask God to help us surrender our feelings of hatred or revenge, and to give us His love for our neighbor.