Contradiction with Exodus 20:13
The commandment "Thou shalt not kill" contradicts the implication of military duties in 1 Chronicles 27:2.
Exodus 20:13: Thou shalt not kill.
Contradiction with Matthew 5:39
Jesus' teaching to "turn the other cheek" contradicts the notion of a military force ready for defense or offense.
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 Isaiah 2:4
The prophecy of nations not learning war anymore contradicts the establishment of military divisions.
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]