Contradiction with Proverbs 17:9
It speaks about covering offenses and promoting love, which contradicts the deceit and betrayal evident when Joab seeks vengeance.
Proverbs 17:9: He that covereth a transgression seeketh love; but he that repeateth a matter separateth [very] friends. [seeketh: or, procureth]
Contradiction with Matthew 5:9
This verse blesses peacemakers, contrasting sharply with Joab's actions that disrupt the peace Abner and David were establishing.
Matthew 5:9: Blessed [are] the peacemakers: for they shall be called the children of God.
Contradiction with Romans 12:19
It advises leaving vengeance to God, whereas Joab takes matters into his own hands against Abner.
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 1 Thessalonians 5:15
Encourages not to repay evil for evil, which Joab does by killing Abner in revenge.
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].
Contradiction with 1 Peter 3:9
Instructs not to repay evil with evil or insult with insult, yet Joab's revenge ignores this guidance.
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.
Contradiction with James 1:20
States that human anger does not produce righteousness, opposing Joab's wrathful response.
James 1:20: For the wrath of man worketh not the righteousness of God.
Contradiction with Matthew 5:44
Commands to love enemies and pray for them, contrary to Joab's murder of Abner.
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;