Contradiction with Exodus 20:13
This verse commands "Thou shalt not kill," while in 1 Samuel 22:20, we see the context of King Saul ordering the death of the priests of Nob, which includes violence and killing.
Exodus 20:13: Thou shalt not kill.
Contradiction with Matthew 5:9
This verse states, "Blessed are the peacemakers," yet in 1 Samuel 22:20, the context involves conflict and violence rather than peacemaking.
Matthew 5:9: Blessed [are] the peacemakers: for they shall be called the children of God.
Contradiction with Proverbs 12:21
This verse claims, "There shall no evil happen to the just," but in 1 Samuel 22:20, innocent priests were killed unjustly, with Abiathar being the sole survivor.
Proverbs 12:21: There shall no evil happen to the just: but the wicked shall be filled with mischief.
Contradiction with Romans 12:17
This verse advises recompensing "to no man evil for evil," in contrast to the retributive violence around the events of 1 Samuel 22:20.
Romans 12:17: Recompense to no man evil for evil. Provide things honest in the sight of all men.
Contradiction with Isaiah 1:17
This verse calls to "seek justice, correct oppression," whereas 1 Samuel 22:20 depicts the unjust murder of priests and oppression by King Saul.
Isaiah 1:17: Learn to do well; seek judgment, relieve the oppressed, judge the fatherless, plead for the widow. [relieve: or, righten]