Disciple Jesus Loved
How can I verify for a protestant who believes that the Disciple Jesus Loved at the cross is a brother of Christ that it it is actually the Apostle St John, brother of James. Seems John usually refers to hinself only as Disciple Jesus loved.
The person I am discussing with assumes that since Jesus says: "Son-behold thy mother" He is indicating that the disciple is a true brother, and son of Mary. I'm sure that somewhere, scripture indicates that this is John, but cannot locate