Contradiction with Matthew 5:44
2 Kings 6:20 involves leading enemies into a trap, while Matthew 5:44 instructs to love your enemies and pray for them.
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 Proverbs 25:21-22
2 Kings 6:20 features deception in warfare, while Proverbs 25:21-22 encourages feeding and giving drink to your enemy, suggesting kindness.
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 Romans 12:17
2 Kings 6:20 deals with an ambush of enemies, but Romans 12:17 advises against repaying evil for evil and promotes honorable behavior towards everyone.
Romans 12:17: Recompense to no man evil for evil. Provide things honest in the sight of all men.
Contradiction with Luke 6:27-28
In contrast to the strategic military act in 2 Kings 6:20, Luke 6:27-28 calls for loving, doing good to, and praying for those who are enemies or who mistreat you.
Luke 6:27-28: But I say unto you which hear, Love your enemies, do good to them which hate you,
Contradiction with 1 Thessalonians 5:15
While 2 Kings 6:20 is about dealing with captives, 1 Thessalonians 5:15 encourages one to ensure that no one repays evil for evil, but always seeks to do good to one another and to everyone.
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].