In answer to your question. It's a matter of punctuation. It depends on how you punctuate the passage. I believe it's God, not Jesus who is speaking there. You think it's Jesus. Moreover, Alpha and Omega can mean several things, it doesn't automatically render the person fully divine or co-equal with YHWH, who says that.
...hath made us kings and priests unto God .... [The KJV continues in Rev. 1:8] I am Alpha and Omega, the beginning and the ending, saith the Lord, which is, and which was, and which is to come, the Almighty. (1:9) I JOHN, who also am your brother....
Notice, since the KJV doesn't use quotation marks at all (they hadn't yet been invented in 1611), you are free to mentally insert them whenever and wherever you wish (as was the case in the original manuscripts and their copies for centuries thereafter). Therefore, you may interpret the whole statement of Rev. 1:8 as being the words of God, or you may decide that God's actual words end at "the beginning and the ending," and that the rest of the words in Rev. 1:8 are descriptive words added by John.
The "speaker confusion trick":
If you look at Rev. 1:8 in The Jerusalem Bible, RSV, NRSV, GW, KJ21, NEB, NET, REB, and WEB, you will find that their trinitarian translators, editors, and publishers have decided that only the first part of Rev. 1:8 is spoken by God, and they use beginning and ending quotation marks to show that.
If you look at Rev. 1:8 in the CEB, CEV, CSB, ESV, NASB, NAB (1970), NAB (1991), NCV, NKJV, NJB, MEV, and the NIV, however, you will see that their trinitarian translators, editors, and publishers have decided that all of Rev. 1:8 was spoken by the Lord God, and they use beginning and ending quotation marks to show that meaning.
But to use the "speaker confusion trick" to "prove" that John is the Lord Almighty we would point to the fact that John was definitely speaking at Rev. 1:7, and then (by using our own punctuation or the KJV's lack of quotation marks) we merely say that John continued speaking in Rev. 1:8 and identified himself as "the Lord," "Alpha and Omega," and "the Almighty"!! Finally we would point to Rev. 1:9 and say that John continues speaking and positively identifies himself as "John, also" or, in other words, "John, in addition to [his titles of Rev. 1:8]"!
So if modern Bible translators belonged to (or at least worked for) churches that taught that John was equally God ("Johnitarians"?), they would simply have punctuated this scripture in a way that showed that. For example, they might put quotation marks starting at verse 8 and ending after verse 9.
There is another thing that helps show the 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.
Moreover...
"I am the Alpha and the Omega," says the Lord God, who is and who was and who is to come, the Almighty. - Rev. 1:8, RSV.
We know this is the Father alone because only he is called `the Lord God' and `Almighty' in holy scripture. Notice that the Father (not the Son) in this verse is described as one who is to come. And, again, these 2 previous verses show the same thing:
Grace to you and peace from him who is and who was and who is to come, and from the seven spirits who are before his throne, and from Jesus Christ the faithful witness...." - Rev. 1:4, 5, RSV.
Again there can be no doubt that this is the Father alone (not the Son) who is said `to come.' He is clearly separated from the Christ and his holy spirit in this verse. Therefore, the sense in which he will `come' must be as described above. And so it is clear that God will "come" and Jesus Christ will come, but they are still two different individuals! YHWH, our Heavenly Father will come.
Rth 1:6 Then she arose with her daughters in law, that she might return from the country of Moab: for she had heard in the country of Moab how that YHWH had visited his people in giving them bread.
YHWH VISITS! YHWH COMES! Through His works, in and through His agents/angels/prophets/messiah/whoever he chooses to use as an instrument of His will and works.
Joh 14:7-11 (7) If ye had known me, ye should have known my Father also: and from henceforth ye know him, and have seen him. (8) Philip saith unto him, Lord, shew us the Father, and it sufficeth us. (9) Jesus saith unto him, Have I been so long time with you, and yet hast thou not known me, Philip? he that hath seen me hath seen the Father; and how sayest thou then, Shew us the Father? (10) Believest thou not that I am in the Father, and the Father in me? the words that I speak unto you I speak not of myself: but the Father that dwelleth in me, he doeth the works. (11) Believe me that I am in the Father, and the Father in me: or else believe me for the very works' sake.
YHWH is present through His works and agents. Jesus is the highest-ranking agent of YHWH, performing the works of His heavenly Father, hence YHWH is present in and through the ministry of Jesus. When Jesus returns, YHWH will be there working in and through His Son. This is very simple, but Trinitarians like to complicate everything, unnecessarily.
Isa_23:17 And it shall come to pass after the end of seventy years, that YHWH will visit Tyre, and she shall turn to her hire, and shall commit fornication with all the kingdoms of the world upon the face of the earth.
Jer_27:22 They shall be carried to Babylon, and there shall they be until the day that I visit them, saith YHWH; then will I bring them up, and restore them to this place.
Jer_29:10 For thus saith YHWH, That after seventy years be accomplished at Babylon I will visit you, and perform my good word toward you, in causing you to return to this place.
Act 15:13-16 And after they had held their peace, James answered, saying, Men and brethren, hearken unto me: (14) Simeon hath declared how God at the first did visit the Gentiles, to take out of them a people for his name. (15) And to this agree the words of the prophets; as it is written, (16) After this I will return, and will build again the tabernacle of David, which is fallen down; and I will build again the ruins thereof, and I will set it up:
YHWH visits His creation, through His works and glory, directly or through a mediator like an angel, prophet or through whichever means he chooses.
In view of everything presented above (and a ton of other facts not presented here), I don't believe your Biblical "evidence" supports your conclusion that Jesus is Almighty God. Jesus is the Son Of The Living God, according to the Bible, not ontologically co-equal, co-eternal, and consubstantial with YHWH Almighty as Trinitarians assert.
