Throughout the first 17 centuries of Christianity, the reliability of the Gospels was never really questioned in any serious way. However, especially from the 19th century forward, a number of scholars have viewed the Gospels, not as the inspired, inerrant Word God, but as being invented by men. Also, they have rejected that the Gospel writers had firsthand knowledge about Jesus Christ.
Some have claimed that John chapter 21 of John’s Gospel was written by a different hand than the apostle John whom they claim only wrote John 1-20. They support this, in part, because the last verse of chapter 20, John 20:31 is in the form of a conclusion, and John 21:24-25 refers to the author of the gospel in the third person (“We know that his testimony is true”).