Contradiction with Proverbs 12:22
This verse emphasizes God's hatred for lying, while in 2 Samuel 20:8, deception occurs during Joab's betrayal of Amasa.
Proverbs 12:22: Lying lips [are] abomination to the LORD: but they that deal truly [are] his delight.
Contradiction with Exodus 20:13
This verse commands, "Thou shalt not kill," which contradicts the violent act of Joab killing Amasa in 2 Samuel 20:8.
Exodus 20:13: Thou shalt not kill.
Contradiction with Matthew 5:44
Jesus instructs to love your enemies, conflicting with Joab's hostile action against Amasa in 2 Samuel 20:8.
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 Romans 12:19
This verse advises against personal vengeance, in contrast to Joab's vengeful murder of Amasa in 2 Samuel 20:8.
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 Matthew 26:52
"For all they that take the sword shall perish with the sword," is a warning against violence contrary to Joab's actions in 2 Samuel 20:8.
Matthew 26:52: Thinkest thou that I cannot now pray to my Father, and he shall presently give me more than twelve legions of angels?