Some people say that since the same titles – Alpha and Omega - are used for both God and Jesus, this proves that they one and the same. It is further claimed that these expressions mean the eternity of the Father and the Son. Upon analysis, we see that this notion raises several problems.
Isaiah 44:6 “This is what the Lord says - Israel’s King and Redeemer, the Lord Almighty: I am the first and I am the last; apart from me there is no God.”
Revelation 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.”
Revelation 1:11 “Saying, I am Alpha and Omega, the first and the last:”
Revelation 22:13 “I am the Alpha and the Omega, the first and the last, the beginning and the end.”
First, the Book of Revelation is an unreliable book. Early Christians and elders of the Church - Marcion, Caius of Rome, Dionysius of Alexandria, Amphilocius of Iconium, Gregory of Nazianzus, Cyril of Jerusalem, Synod of Laodicea in 360 CE - disputed it. The author of the Revelation identifies himself as some unknown John, but probably not the apostle John because the style of the book is completely different from the Gospel of John. Other than his name, very little is known about him. Martin Luther criticized this book. He wrote in the preface to Revelation,
About this book of the Revelation of John, I leave everyone free to hold his own opinions. I would not have anyone bound to my opinion or judgment. I say what I feel. I miss more than one thing in this book, and it makes me consider it to be neither apostolic nor prophetic… Many of the fathers also rejected this book a long time ago… For me this is reason enough not to think highly of it: Christ is neither taught nor known in it.”
To this day, Lutheran scholars put the Revelation of John in a separate category of disputed books.
Second, Alpha and Omega are the first and last letters of the Greek alphabet. Biblical scholars are not completely sure what the phrase “the Alpha and the Omega” means. It cannot be strictly literal, because neither God nor Jesus is a Greek letter. It is like saying God is ‘A’ and ‘Z’. Lenski concludes, “It is fruitless to search Jewish and pagan literature for the source of something that resembles this name Alpha and Omega. Nowhere is a person, to say nothing of a divine Person, called ‘Alpha and Omega’, or in Hebrew, ‘Aleph and Tau’.” Although there is no evidence from the historical sources that anyone is named “the Alpha and Omega,” Bullinger says that the phrase “is a Hebraism, in common use among the ancient Jewish Commentators to designate the whole of anything from the beginning to the end; e.g., ‘Adam transgressed the whole law from Aleph to Tau’.” The best scholarly minds have concluded that the phrase has something to do with starting and finishing something, or the entirety of something.
Third, the doctrine of Alpha and Omega is a sad and unfortunate example of mankind’s tampering with the Word of God. It shows how doctrine is contracted by men to justify false beliefs. The phrase “Saying, I am Alpha and Omega, the first and the last” (Revelation 1:11) which is found in the King James Version was not in the original Greek texts. Therefore, the Alpha Omega phrase is not found in virtually any ancient texts, nor is it mentioned, even as a footnote, in any modern translation!
KJV “and heard behind me a great voice, as of a trumpet, Saying, I am Alpha and Omega, the first and the last:”
NIV “and I heard behind me a loud voice like a trumpet, which said: ‘Write on a scroll what you see and send it to the seven churches’”
NASB and I heard behind me a loud voice like the sound of a trumpet, saying, “Write in a book what you see, and send it to the seven churches:”
ASV “and I heard behind me a great voice, as of a trumpet saying, What thou seest, write in a book and send it to the seven churches:”
RSV “and I heard behind me a loud voice like a trumpet saying, “Write what you see in a book and send it to the seven churches”
NAB (Catholic) “and heard behind me a voice as loud as a trumpet, which said, “Write on a scroll what you see and send it to the seven churches”
 Bible Research, an internet resource by Michael D. Marlowe. (http://www.bible-researcher.com/canon5.html)
 A Critical and Exegetical Commentary on The Revelation of St. John by R. H. Charles. T. & T. Clark, 1920
 Luther’s Works, vol 35 (St. Louis: Concordia, 1963), pp. 395-399.
 R.C.H. Lenski, The Interpretation of St. John’s Revelation (Augsburg Pub. House, Minneapolis, MN 1963), p. 51.
 E. W. Bullinger, Commentary on Revelation (Kregel Pub., Grand Rapids, MI, 1984), pp. 147 and 148.