Contradiction with Matthew 5:44
Deuteronomy 31:7 encourages courage and strength in conquest, whereas Matthew 5:44 promotes love and prayer for enemies.
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 Isaiah 2:4
Isaiah 2:4 envisions a future of peace without war, contradicting the call to lead into battle in Deuteronomy 31:7.
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]
Contradiction with Matthew 26:52
Jesus' rebuke against the use of the sword contradicts the charge to lead and be strong in military conquest as in Deuteronomy 31:7.
Matthew 26:52: Thinkest thou that I cannot now pray to my Father, and he shall presently give me more than twelve legions of angels?
Contradiction with Romans 12:19
Romans 12:19 encourages leaving vengeance to God, while Deuteronomy 31:7 implies direct participation in driving out nations.
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.