Contradiction with Matthew 28:19
Contradicts by describing the commissioning of disciples to all nations, differing from John 1:40's focus on an individual's initial encounter.
Matthew 28:19: Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost: [teach...: or, make disciples, or, Christians of all nations]
Contradiction with John 14:6
Presents Jesus as the sole path to God, which contrasts with John's description of varied disciples' roles.
John 14:6: Jesus saith unto him, I am the way, the truth, and the life: no man cometh unto the Father, but by me.
Contradiction with Mark 9:38
Highlights someone casting out demons in Jesus' name who is not part of the direct group, conflicting with the individual focus of John 1:40.
Mark 9:38: And John answered him, saying, Master, we saw one casting out devils in thy name, and he followeth not us: and we forbad him, because he followeth not us.
Contradiction with 1 Corinthians 1:12
Shows early divisions and different leaders followed in the church, contradicting the singular following noted in John 1:40.
1 Corinthians 1:12: Now this I say, that every one of you saith, I am of Paul; and I of Apollos; and I of Cephas; and I of Christ.