The question can best be answered by stating that John penned the book of Revelation, while our Lord Jesus is the Author.  The correct title of the book comes at the very beginning, "The Revelation of Jesus Christ."  John was shown what to write.  He received Revelation while imprisoned on the Isle of Patmos.\n\nThe strongest evidence for dating any ancient historical document is internal.  The second evidence is written tradition, a way of refering to non-scripture.  We know that unlike other apostles, John did not die a martyrs death.\n\nThe first history of the church, outside of the first century book of Acts (by Luke who also wrote Luke), was that of Eusebius in the 4th century.  Eusebius relates the story of John being carried to church in his old age, telling fellow Christians to love one another, for in that all was fulfilled.\n\nDates given for the writing vary, but scholars set a late date of being during the Roman Emperor Domitian's reign.  This is said to be about AD 95-96.  This is highly significant as it would be the very last "theopneustos" (God breathed) scripture written.\n\nIt is also significant, because the REVELATION OF JESUS CHRIST serves as the expounder and capstone of the prophetic writings.  It could be said that the most vital book to understanding Revelation is the book of Daniel, because this book is the only one which not only gives the events, but also the times (this is noted by Josephus in his description of Daniel).\n\nSince the author, our Lord Jesus, is eternal (Rev. 21:6), it could be said that His Revelation not only was written, but that it is and always has been written, and the book carries a great curse for whoever adds to it -- REVELATION ADDS ALL THE PLAGUES OF THE BOOK!!!  To those who take away -- IT SAYS GOD SHALL TAKE AWAY HIS PART OF THE BOOK OF LIFE, AND OUT OF THE HOLY CITY, AND FROM THE THINGS WHICH ARE WRITTEN IN THIS BOOK.\n\nYears ago, an old mentor of mine showed me a greek version of Revelation he had.  It showed the variants (places where somehow different manuscripts disagree).  Nevertheless, certain variants do not cast doubt upon the reliability of transmission.\n\nMy study of Revelation has revealed that a concordance, careful study, and reverence for Almighty God reveal the same exact themes found in varying scriptures, both old and new, (also helpful are the book of Enoch and also Yashir "Jasher").  Someone who is truly up to such a task shall find that only the Omniscient Creator could tie such a sweeping exposition of scripture into a dispersed narrative of the end of the age and the renewal of all things under Messiah.\n\nOur Lord Jesus Christ is the Author.  John wrote the book.\n\nI hope this helps.\n\nTake care,\nMark