The same came for a witness, to bear witness of the Light, that all men through him might believe.
Then came to hym the tempter and sayde: yf thou be the sonne of God commaunde that these stones be made breed.Matthew 4:3 TYN
He was not that Light, but was sent to bear witness of that Light.John 1:8 KJV
There was a man sent from God, whose name was John.John 1:6 KJV