Contradiction with Matthew 5:39
Joel 3:7 speaks of retribution, while Matthew 5:39 teaches to resist not evil and to turn the other cheek, encouraging forgiveness.
Matthew 5:39: But I say unto you, That ye resist not evil: but whosoever shall smite thee on thy right cheek, turn to him the other also.
Contradiction with Romans 12:19
Joel 3:7 suggests God will retaliate against enemies, but Romans 12:19 advises believers not to avenge themselves, for vengeance belongs to the Lord.
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 Luke 6:27-28
Joel 3:7 supports recompense against enemies, yet Luke 6:27-28 instructs to love and bless them, advocating non-violence and compassion.
Luke 6:27-28: But I say unto you which hear, Love your enemies, do good to them which hate you,
Contradiction with Proverbs 25:21-22
Joel 3:7 involves payback, whereas Proverbs 25:21-22 encourages feeding and providing for the enemy, which will "heap coals of fire" on their head, implying overcoming evil with good.
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 1 Peter 3:9
Joel 3:7 talks about returning what was done, contrasting with 1 Peter 3:9, which advises not to repay evil for evil but to bless.
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.