In the book of Revelation, the titles "Alpha and Omega" signify the beginning and the end. Alpha is the first letter and Omega is the last letter of the Greek alphabet. Together, they function as an inclusio—a rhetorical device that encompasses the totality of a subject—signifying that God is the sum of all existence from beginning to end.
Revelation 1:8 attributes the title "Alpha and Omega" to the Lord God, who is identified as the Almighty. Revelation 21:6 echoes this sentiment, as the one seated on the throne of Heaven proclaims, "It is done. I am the Alpha and the Omega, the Beginning and the End." The Old Testament says it is God will be the one to come to judge the earth.
10. Behold, the Lord GOD comes with might, and his arm rules for him; behold, his reward is with him, and his recompense before him.
Paul also says this in agreement with Isaiah in his letter to the Romans.
10. Why do you pass judgment on your brother? Or you, why do you despise your brother? For we will all stand before the judgment seat of God; 11. for it is written, “As I live, says the Lord, every knee shall bow to me, and every tongue shall confess to God.” 12. So then each of us will give an account of himself to God.
Revelation 22:13 clearly attributes these titles to Jesus, as He declares, "I am the Alpha and the Omega, the First and the Last, the Beginning and the End." The speaker is definitively identified as Jesus based on the surrounding text. The New testament also teaches that the Father will not judge the word (John 5:20-22), but Jesus will and is coming (Matthew 25:31; Mark 14:62; Acts 17:31; 2 Corinthians 5:10; 1 Peter 4:5; Revelation 1:7, 22:20). Earlier in the same chapter of Revelations, verses 12 and 16 clearly attribute the speech to Jesus:
12. “Behold, I am coming soon, bringing my recompense with me, to repay each one for what he has done. 13. I am the Alpha and the Omega, the first and the last, the beginning and the end.”
By using the same titles "Alpha and Omega" for both Jesus and the Lord God, Revelation intertwines Jesus's identity with that of God.
First and the Last - Beginning and the End
In the Old Testament, particularly in the book of Isaiah, God is repeatedly described as the "First and the Last" (Isaiah 41:4; Isaiah 44:6; Isaiah 48:12). The use of this title asserts that God is the origin and culmination of all things, existing before creation and remaining after its end. This concept is crucial in understanding the nature of God as depicted in the Hebrew Scriptures: He is the beginning and the end, the one who was, who is and who is to come (Revelation 4:8).
In the New Testament, this title is once again ascribed to God in Revelation 21:6. However, this title is claimed by Jesus Christ in Revelation 1:17-18, "I am the First and the Last. I am He who lives, and was dead, and behold, I am alive forevermore,". Revelation 2:8 and Revelation 22:13 reiterate this title for Jesus once again.