Good for Evil, Evil for Evil

In reference to Nabal, David almost rewarded evil for evil. (25:3-39)

Now the name of the man was Nabal; and the name of his wife Abigail: and she was a woman of good understanding, and of a beautiful countenance: but the man was churlish and evil in his doings; and he was of the house of Caleb...Now therefore know and consider what thou wilt do; for evil is determined against our master, and against all his household: for he is such a son of Belial, that a man cannot speak to him...Now David had said, Surely in vain have I kept all that this fellow hath in the wilderness, so that nothing was missed of all that pertained unto him: and he hath requited me evil for good...And when David heard that Nabal was dead, he said, Blessed be the Lord, that hath pleaded the cause of my reproach from the hand of Nabal, and hath kept his servant from evil:

In reference to Saul, David rewarded good for evil. 1 Samuel 24:11-17 

Moreover, my father, see, yea, see the skirt of thy robe in my hand: for in that I cut off the skirt of thy robe, and killed thee not, know thou and see that there is neither evil nor transgression in mine hand, and I have not sinned against thee; yet thou huntest my soul to take it...And he said to David, Thou art more righteous than I: for thou hast rewarded me good, whereas I have rewarded thee evil.

Reward good for evil.

Psalm 38:20 They also that render evil for good are mine adversaries; because I follow the thing that good is.

Psalm 35:12 They rewarded me evil for good to the spoiling of my soul.

Proverbs 17:13 Whoso rewardeth evil for good, evil shall not depart from his house.

1 Thessalonians 5:15 See that none render evil for evil unto any man; but ever follow that which is good, both among yourselves, and to all men.

1 Peter 3:9 not rendering evil for evil, or railing for railing: but contrariwise blessing; knowing that ye are thereunto called, that ye should inherit a blessing.

Matthew 5:44-46 But I say unto you, Love your enemies, bless them that curse you, do good to them that hate you, and pray for them which despitefully use you, and persecute you; 45 that ye may be the children of your Father which is in heaven: for he maketh his sun to rise on the evil and on the good, and sendeth rain on the just and on the unjust. 46 For if ye love them which love you, what reward have ye? do not even the publicans the same?

Do not avenge. Leave that to God, who does not err in doing so.

Romans 12:19 Dearly beloved, avenge not yourselves, but rather give place unto wrath: for it is written, Vengeance is mine; I will repay, saith the Lord.