Contradiction with Exodus 14:14
This verse speaks of the Lord fighting for you, whereas Joshua 8:7 involves the Israelites taking offensive action themselves.
Exodus 14:14: The LORD shall fight for you, and ye shall hold your peace.
Contradiction with Matthew 5:44
This verse instructs to love your enemies, in contrast to the ambush and destruction commanded in Joshua 8:7.
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 believers not to seek vengeance, while Joshua 8:7 involves a battle strategy against enemies.
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 3:5
This verse advises trusting in the Lord rather than relying on one's own understanding, whereas Joshua 8:7 involves human strategy and action.
Proverbs 3:5: Trust in the LORD with all thine heart; and lean not unto thine own understanding.
Contradiction with Isaiah 2:4
This verse looks forward to a time when nations shall not learn war anymore, contrasting with the warfare in Joshua 8:7.
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]