In this challenge you will see that both God the Father and Jesus are called the Alpha and Omega, the first and the last. I am going to establish in the Old Testament we see Jehovah is the Alpha and Omega, the first and the last, and in the New Testament Jesus makes the same claim. There can only be one first and last; only one Alpha and Omega.
You may wonder what it meant if Jesus called Himself the Alpha and Omega. Here is what Ken Samples says in his book “Reasoning from the Scriptures with the Jehovah’s Witnesses:”
But for the ancient Jew, Christ was describing Himself in a way he would have readily understood. Though the letters alpha and omega are the first and last letters of the Greek alphabet, John recorded the Book of Revelation for Jewish readers who were also familiar with the Hebrew language and alphabet.
When used of God (or Christ), the first and last letters express eternality and omnipotence. Christ’s claim to be the Alpha and the Omega is an affirmation that He is the all-powerful One of eternity past and eternity future (Jehovah-God). “In describing Himself as ‘the first and the last’ Christ is relating Himself to time and eternity. He is the eternal God who has always existed in the past and who will always exist in the future.” For any created being, however exalted, to claim to be the Alpha and the Omega as these terms are used of Jesus Christ would be utter blasphemy.
Jehovah’s Witnesses have to argue that Jesus is not the Alpha and Omega. They believe he is a created being, a lesser god and not Jehovah God. When I’ve used this argument with Jehovah’s Witnesses, they have yet to give any credible explanation.
2. Alpha and Omega argument
I will quote from the Watchtower Bible, The New World Translation (NWT): Revelations 1: 7 & 8, Look! He is coming with the clouds, and every eye will see him, and those who pierced him; and all the tribes of the earth will beat themselves in grief because of him. Yes, Amen. 8“I am the Al′pha and the O‧me′ga,” says Jehovah God, “the One who is and who was and who is coming, the Almighty.”
The following is the argument used by David Reed in his book, “Jehovah’s Witnesses Answered Verse by Verse.”
Revelation 1:7-8, quoted above, says that someone “is coming.” Who? Verse 7 says it is someone who was “pierced.” Who was it that was pierced when he was nailed up to die? Jesus! But verse 8 says that it is Jehovah God who “is coming.” Could it be that there are two who are coming? No! Verse 8 refers to “the One who … is coming.”
Revelation 1:8 states clearly that Jehovah God is the Alpha and the Omega. Now note what he says at Revelation 22:12-13: “Look! I am coming quickly … I am the Alpha and the Omega, the first and the last. …” So, Jehovah God is coming quickly. But notice the response when he says it again: “Yes; I am coming quickly. ‘Amen! Come, Lord Jesus'” (22:20, NWT).
At this point you might mention that Alpha is the first letter of the Greek alphabet, while Omega is the last letter. Therefore, “the Alpha and the Omega” means the same thing as “the First and the Last.” Then, again referring to the New World Translation, continue like this: Who is speaking in Revelation 2:8? “These are the things that he says, `the First and the Last,' who became dead and came to life again. . . .” Obviously, it is Jesus. Who was Jesus identifying himself as being, when he called himself “the First and the Last”? This is how Almighty God described himself in the Old Testament.
Jesus knew that the apostle John, who wrote the Revelation, and later Bible readers would all remember these verses: “… I am the same One. I am the first. Moreover, I am the last. Moreover, my own hand laid the foundation of the earth, and my own right hand extended out the heavens…” (Isa. 48:12-13). And: “. . . I am the same One. Before me there was no God formed, and after me there continued to be none. I-I am Jehovah, and besides me there is no savior” (Isa. 43:10-11).
This argument clearly establishes both Jehovah God and Jesus are the Alpha and Omega, the first and the last. However, there is a problem; there can only be one Alpha/Omega and first/last. Ask the Jehovah’s Witness, what is the true identity of Jesus? The alpha and omega argument establishes Jesus is fully God. Only the doctrine of the Trinity can solve the issue of the Father and Son being the Alpha and Omega. Remember the Trinity teaches one God subsists (ongoing existence) in three persons, Father, Son, and Holy Spirit; co-equal and co-eternal. With only one God there is only one Alpha and Omega.
My encouragement to you is the write the key points of the argument in the margins of your Bible. This way you don’t have to memorize all the verses that establish Jesus is the Alpha and Omega.
Many years ago Walter Martin entered the Watchtower Organization and shared this argument with the man at the front desk. This individual wrote in the margins of his Bible, Jesus is the Alpha and Omega, Almighty God. Ten years later he reread the statement and after pondering who Jesus is the light went on and he trusted Jesus Christ for the forgiveness of his sins. Today he is leads an outreach organization to Jehovah Witnesses. When you share the truth with others you may never know the impact God will have upon their hearts and minds. Use this argument graciously and let the Holy Spirit do the rest.
 Ken Samples, Reasoning from the Scriptures with the Jehovah’s Witnesses, (Harvest House Publ., 1993) p. 251.
 John F. Walvoord, The Revelation of Jesus Christ (Chicago: Moody Press, 1980), p. 60.
 David A. Reed, Jehovah’s Witnesses Answered Verse by Verse, (Baker Book House, 1986) Kindle location 966-988