Contradiction with Matthew 5:44
While Psalms 43:1 asks for deliverance from deceitful and unjust men, Matthew 5:44 instructs to love your enemies and pray for those who persecute you.
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
Contrary to Psalms 43:1 seeking justice and deliverance from adversaries, Romans 12:19 advises against seeking vengeance and leaves it to God’s wrath.
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 20:22
Psalms 43:1 seeks vindication from adversaries, whereas Proverbs 20:22 advises against repaying evil and suggests waiting for the Lord to save you.
Proverbs 20:22: Say not thou, I will recompense evil; [but] wait on the LORD, and he shall save thee.
Contradiction with 1 Peter 3:9
In contrast to asking for deliverance from unjust persons in Psalms 43:1, 1 Peter 3:9 teaches not to repay evil for evil or reviling for reviling.
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.