He is generally understood to be the disciple of John the Baptizer that was with Andrew when John announced to them: “See, the Lamb of God!” His ready acceptance of Jesus as the Christ reveals that he had a knowledge of the Hebrew Scriptures. (Joh 1:35, 36, 40-42)

Viewing John’s writing in this light, it becomes evident that he himself was the unnamed companion of Andrew to whom John the Baptizer introduced Jesus Christ. (Joh 1:35-40)