Contradiction with Exodus 20:13
This verse commands "Thou shalt not kill," which contradicts Judges 11:6 where Jephthah is asked to lead a battle involving killing.
Exodus 20:13: Thou shalt not kill.
Contradiction with Matthew 5:44
Jesus instructs to "Love your enemies," which contradicts the notion of leading a war against enemies as implied in Judges 11:6.
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 leaving vengeance to God, which contradicts the call to lead an offensive in Judges 11:6.
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 Romans 14:19
Encourages pursuing peace, which contradicts the call to battle in Judges 11:6.
Romans 14:19: Let us therefore follow after the things which make for peace, and things wherewith one may edify another.
Contradiction with Philippians 2:3
Advises doing nothing out of selfish ambition, contrasting with the war leadership sought in Judges 11:6.
Philippians 2:3: [Let] nothing [be done] through strife or vainglory; but in lowliness of mind let each esteem other better than themselves.