As you probably know, the original Bible writers didn't use any punctuation or capitalization and frequently ran the words of one speaker right into those of another speaker without any warning or indication. Eerdmans 1978 edition of Young's Analytical Concordance to the Bible, for example, warns Bible readers:
"The language of the MESSENGER frequently glides into that of the SENDER ..." and, "what a SERVANT says or does is ascribed to the MASTER." - "Hints and Helps to Bible Interpretation" - Preface.
There is another thing that helps show the originally-intended meaning here. Although it is very common that the words of one speaker slide right into those of another speaker (e.g., Is. 10:4, 7), it also happens that sometimes the writer identifies the new speaker. As we see in Daniel, for example, Daniel nearly always identifies himself as the new speaker when he uses the words "I, Daniel" whenever it might be confusing to the reader (especially after a different person has been speaking) - Dan. 7:15, 28; 8:15, 27; 12:5.
If we then examine Revelation (which is recognized as being similar to, patterned after, and frequently referring to, the Book of Daniel), we find that John also uses this technique. "I, John" identifies a new speaker in every instance John uses it: Rev. 1:9; 22:8. So Rev. 1:9 is merely the statement of a new speaker.
Now look again at Rev. 22:8-16.
John is identified as the speaker in 22:8. The angel speaks in (:9). The angel apparently continues speaking in (:10). The angel may be still speaking in (:11) --- or it could be John or even someone else (as implied in verse 10 in the NAB,1970 ed.).
Now is the angel still speaking in (:12) or is it God, or is it Jesus, or even John?
There is simply no way of telling who the speaker is from any of the early Bible manuscripts. It's entirely a matter of translator's choice. Some translators have decided it is the angel who continues to speak, and they punctuate it accordingly.
So the NASB, JB, and NJB use quotation marks to show that these are all words spoken by the angel.
However, the NKJV, NEB, REB, RSV, and NRSV show by their use of quotation marks that someone else is now speaking in verse 12.
Most Bibles indicate that the person who spoke verse 12 (whether God, angel, Jesus, or John) also spoke verse 13 ("I am Alpha and Omega").
So the big question is: Is it clear that the speaker of verses 12 and 13 continues to speak? Some Bibles indicate this. But other highly respected trinitarian translations do not!
The RSV, NRSV, NASB, NEB, REB, NKJV, and NAB (1991 ed.) show (by quotation marks and indenting) that Rev. 22:14 and 15 are not the words of the speaker of verses 12 and 13 but are John's words. (The Jerusalem Bible and the NJB show us that the angel spoke all the words from verse 10 through verse 15.)
Then they all show Jesus as a new speaker beginning to speak in verse 16.
So, if you must insist that the person speaking just before verse 16 is the same person who is speaking in verse 16, then, according to the trinitarian NEB, RSV, NKJV, and NASB Bibles, you are saying John is Jesus! (According to the JB and NJB you would be insisting that the angel is Jesus!)
Remember, "I, John" indicated a new speaker in Revelation.
So Rev. 22:16 - "I, Jesus" also introduces a new speaker. This means, of course, that the previous statement ("I am the Alpha and Omega") was made by someone else!
Even the KJV (and NKJV) translators have shown by their use of the word 'his' ('His' in the NKJV) in verse 14 that they didn't mean that Jesus was the same speaker as the Alpha and Omega. The speaker of verse 13 is Almighty God. The comment in verse 14 of these Bibles (as literally translated from the Received Text) explains the importance of doing "His Commandments" (not "My Commandments")! Therefore, the speaker of verse 14 is obviously not God as clearly stated by those Bibles which were translated from the Received Text, e.g., KJV; NKJV; KJIIV; MKJV; Young's Literal Translation; Webster Bible (by Noah Webster); and Revised Webster Bible.
So we can easily see that there is no reason to say Jesus spoke the words recorded at Rev. 22:13 (or the above-named trinitarian Bibles would surely have so translated it!) and, in fact, the context really identifies the speaker as being the same person who spoke at Rev. 1:8, God Almighty, Jehovah, the Father.
The only other use of the title "Alpha and Omega" confirms this understanding.
"And He who sits on the throne said, `Behold, I am making all things new.' .... And He said to me, `It is done. I am the Alpha and the Omega, the beginning and the end. .... He who overcomes shall inherit these things, and I will be his God and he will be My son.'" - Rev. 21:5-7, NASB.
"Revelation 21:6, 7 indicates that Christians who are spiritual conquerors are to be `sons' of the one known as the Alpha and the Omega. That is never said of the relationship of spirit-anointed Christians to Jesus Christ. Jesus spoke of them as his `brothers.' (Heb. 2:11; Matt. 12:50; 25:40) But those `brothers' of Jesus are referred to as `sons of God [the Father].' (Gal. 3:26; 4:6)." - pp. 412-413, Reasoning from the Scriptures, WBTS, 1985.
So Rev. 21:6, 7 confirms the understanding that the Alpha and Omega is the Father, not Jesus.
Furthermore, The only one "seated on the throne" in Rev. is the Father, Jehovah alone. (See, for example, Rev. 4 & 5 where the "Lion that is of the tribe of Judah," the lamb [the Son] approaches the one seated on the throne!)
In short, there is no reason, other than a desire to support the trinity tradition, to believe that Jesus is being called "Alpha and Omega" in Rev. 22. And there is good evidence to believe that it is his Father only who uses this title for himself.
For more, see:
Alpha and Omega - Speaker Confusion Trick (Examining the Trinity)
Alpha and Omega (Insight; Watchtower Online Library)
Alpha and Omega: To whom does this title properly belong? (rs p. 405-p. 426; Watchtower Online Library)
Exposing the False Reasoning Behind Trinity 'Proof'-Texts (Defend Jehovah's Witnesses)
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