What books did the Apostle John write?

Thank you for writing us at Christian Questions.  You wanted to know if the author of the Gospel of John is the same John who wrote 1 John, 2 John, 3 John as well as the Book of Revelation.  

Yes, we believe he is the same John, the son of Zebedee (Mark 1:19-20).  He was an Apostle and one of Jesus’ inner circle.  He referred to himself as “the disciple whom Jesus loved” (John 13:23). Even though the author of 1 John, 2 John and 3 John does not specifically identify himself, the evidence of the letters themselves confirms his identification because the writing style of the Gospel of John is markedly similar to that of the letters.  

In the Book of Revelation, the author does identify himself four times as John. (See Revelation 1:1,4,9; 22:8.)   Although John penned the book, his writings were not his own but were a revelation of Jesus Christ, which John received while in a trance.  John was an old man exiled to the isle of Patmos when he wrote Revelation.