Contradiction with Matthew 10:34
Jesus says he came not to bring peace, but a sword, which contradicts the command to love one another.
Matthew 10:34: Think not that I am come to send peace on earth: I came not to send peace, but a sword.
Contradiction with Luke 14:26
Jesus states that one must hate their family to be his disciple, which contradicts loving one another.
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 Exodus 21:24
An eye for an eye is a call for retribution, contrasting the command to love one another.
Exodus 21:24: Eye for eye, tooth for tooth, hand for hand, foot for foot,
Contradiction with Leviticus 24:19-20
Promotes reciprocal justice, which contradicts the selfless love commanded in John 13:34.
Leviticus 24:19-20: And if a man cause a blemish in his neighbour; as he hath done, so shall it be done to him;
Contradiction with Deuteronomy 13:6-10
Commands to kill someone who entices others to worship other gods, which contradicts loving one another.
Deuteronomy 13:6-10: If thy brother, the son of thy mother, or thy son, or thy daughter, or the wife of thy bosom, or thy friend, which [is] as thine own soul, entice thee secretly, saying, Let us go and serve other gods, which thou hast not known, thou, nor thy fathers;