Contradiction with Exodus 14:14
Numbers 1:53 suggests active guarding of the tabernacle, whereas Exodus 14:14 emphasizes God fighting for His people without their need to act.
Exodus 14:14: The LORD shall fight for you, and ye shall hold your peace.
Contradiction with Matthew 5:39
Numbers 1:53 implies readiness for conflict, while Matthew 5:39 encourages turning the other cheek instead of resisting evil with force.
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
Numbers 1:53 involves protection against wrath, whereas Romans 12:19 advises believers to leave vengeance to God.
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 Psalm 127:1
Numbers 1:53 assumes human responsibility for protection, in contrast, Psalm 127:1 suggests that ultimately protection comes from God, not human guard.
Psalm 127:1: [A Song of degrees for Solomon.] Except the LORD build the house, they labour in vain that build it: except the LORD keep the city, the watchman waketh [but] in vain. [for...: or, of Solomon] [that...: Heb. that are builders of it in it]