Dwight, this was a BIG booboo on my part. We do NOT know that these words were spoken by Jesus.I wrote: "I am the Alpha and Omega, the Beginning and the End" is found ONLY in the New Testament.
We know, of course, that these words were spoken by Jesus and no other.
These words are found ONLY in the book of Revelation.
There was much dispute about the book of Revelation in the early church. It was the last book of the Bible to be accepted as part of the Christian canon of Scripture. In the Eastern branch of the Church, distrust of Revelation persisted until the 15th century.
Early church tradition puts the time that the book was written as being at the end of Domitian's reign. That would be A.D. 96. Though early church tradition also assigns the authorship to the apostle John, it is unlikely that John would have been still alive at that date.
Another factor to be noted, is that the author of Revelation states 4 times in the book that his name is “John.” Rev 1:1, 1:4, 1:9, and 22:8.
However, in the two books known to have been written by the apostle John, that is, the gospel of John and 1 John, John never claimed to be the author. And the author of 2 and 3 John refers to himself simply as “the elder.” The word “John” does not occur even once in 1, 2, or 3 John.