Contradiction with Mark 12:31
This verse emphasizes the command to love your neighbor, which may contradict a specific expression of affection directed solely towards an individual like in 3 John 1:1.
Mark 12:31: And the second [is] like, [namely] this, Thou shalt love thy neighbour as thyself. There is none other commandment greater than these.
Contradiction with Matthew 5:44
It instructs to love enemies, which can contrast with the personal and specific affection or relation observed in 3 John 1:1 towards a friend rather than an enemy.
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 2 John 1:10
Advises against welcoming certain people into your house, while 3 John 1:1 opens with a hospitable and personal endorsement.
2 John 1:10: If there come any unto you, and bring not this doctrine, receive him not into [your] house, neither bid him God speed:
Contradiction with Luke 14:26
Suggests hating one's family for discipleship, which contrasts with the familial and affectionate tone expressed in 3 John 1:1.
Luke 14:26: If any [man] come to me, and hate not his father, and mother, and wife, and children, and brethren, and sisters, yea, and his own life also, he cannot be my disciple.
Contradiction with Romans 12:20
Encourages feeding your enemy, presenting a broader charity which may oppose the focused care in 3 John 1:1.
Romans 12:20: Therefore if thine enemy hunger, feed him; if he thirst, give him drink: for in so doing thou shalt heap coals of fire on his head.
Contradiction with James 2:1
Urges not to show favoritism, potentially contradicting the personal favor expressed in 3 John 1:1.
James 2:1: My brethren, have not the faith of our Lord Jesus Christ, [the Lord] of glory, with respect of persons.
Contradiction with 1 Corinthians 13:5
States that love does not seek its own, potentially contrasting with the language of personal affection and favor in 3 John 1:1.
1 Corinthians 13:5: Doth not behave itself unseemly, seeketh not her own, is not easily provoked, thinketh no evil;