Contradiction with Matthew 5:9
Joel 3:9 calls for preparation for war, while Matthew 5:9 blesses peacemakers, highlighting a call for peace.
Matthew 5:9: Blessed [are] the peacemakers: for they shall be called the children of God.
Contradiction with Romans 12:18
Joel 3:9 encourages preparing for war, while Romans 12:18 advises living peaceably with all, if possible.
Romans 12:18: If it be possible, as much as lieth in you, live peaceably with all men.
Contradiction with Isaiah 2:4
Joel 3:9 speaks of preparing for war, whereas Isaiah 2:4 envisions a future where nations do not learn war anymore.
Isaiah 2:4: And he shall judge among the nations, and shall rebuke many people: and they shall beat their swords into plowshares, and their spears into pruninghooks: nation shall not lift up sword against nation, neither shall they learn war any more. [pruninghooks: or, scythes]
Contradiction with James 3:18
Joel 3:9 advocates for readiness for conflict, in contrast, James 3:18 emphasizes sowing peace to yield righteousness.
James 3:18: And the fruit of righteousness is sown in peace of them that make peace.
Contradiction with Proverbs 16:7
Joel 3:9 promotes war readiness, while Proverbs 16:7 states that when a man's ways please the Lord, He makes his enemies be at peace with him.
Proverbs 16:7: When a man's ways please the LORD, he maketh even his enemies to be at peace with him.