Contradiction with Matthew 5:44
This verse contradicts Psalms 139:20 by instructing believers to love their enemies, whereas Psalms 139:20 speaks against those who misuse God's name.
Matthew 5:44: 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;
Contradiction with Luke 6:27
Here, it is encouraged to do good to those who hate you, contrary to the attitude towards adversaries implied in Psalms 139:20.
Luke 6:27: But I say unto you which hear, Love your enemies, do good to them which hate you,
Contradiction with Romans 12:14
The directive to bless those who persecute you stands in contrast to the adversarial tone towards enemies in Psalms 139:20.
Romans 12:14: Bless them which persecute you: bless, and curse not.
Contradiction with Romans 12:19
This verse teaches not to take revenge, but to leave room for God's wrath, differing from the approach suggested in Psalms 139.
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.
Contradiction with Proverbs 24:17
Advises against rejoicing when your enemy falls, which contrasts with the implied tone in Psalms 139:20 regarding adversaries.
Proverbs 24:17: Rejoice not when thine enemy falleth, and let not thine heart be glad when he stumbleth:
Contradiction with Proverbs 25:21-22
Encourages offering food and drink to your enemy, contrasting the restrictiveness towards those misusing God's name.
Proverbs 25:21-22: If thine enemy be hungry, give him bread to eat; and if he be thirsty, give him water to drink:
Contradiction with Exodus 23:4-5
This passage encourages helping your enemy if they face trouble, which is different from the opposition towards adversaries in Psalms 139:20.
Exodus 23:4-5: If thou meet thine enemy's ox or his ass going astray, thou shalt surely bring it back to him again.