“I am the Alpha and the Omega, the first and the last, the beginning and the end.” …
“I, Jesus, have sent My angel to testify to you these things for the churches. I am the root and the descendant of David, the bright morning star.” (22:13, 16)
The first reason for sinners to accept God’s final invitation is because it comes personally from the exalted, majestic, glorious Lord Jesus Christ. The Lord’s threefold identification of Himself repeats the same truth for emphasis. Since the original readers of Revelation spoke Greek, Jesus identifies Himself first as the Alpha and the Omega (cf. 1:8; 21:6). Alpha and Omega are, respectively, the first and last letters of the Greek alphabet. Together with the parallel phrases the first and the last (cf. 1:17) and the beginning (the source of all things) and the end (the goal of all things), it expresses Christ’s infinity, eternity, and boundless life transcending all limitations. This threefold description describes the completeness, timelessness, and sovereign authority of the Lord Jesus Christ.
This description of Jesus Christ is also a statement of His deity. Obviously, there can be only one Alpha and Omega, first and last, and beginning and end—God. In 1:8 God says, “I am the Alpha and the Omega,” while 21:6 describes Him as “the beginning and the end.” In Isaiah 44:6 God declares, “I am the first and I am the last” (cf. Isa. 41:4; 48:12). That all three titles, which can apply only to God, are used here of Jesus Christ offers convincing testimony to His deity. He is not a created being; He is not merely a great prophet or a great moral teacher; He is not a misguided martyr. He is God the Son, the second Person of the eternal Trinity.
Salvation in Jesus Christ is the theme of Scripture. In the Old Testament the ark in which Noah and his family were saved, the Passover lamb, and the kinsman redeemer are all pictures of Christ. In addition, Christ fulfilled more than 300 Old Testament prophecies at His first coming. He is the focus of the New Testament as well. The gospels record His life and ministry, and the rest of the New Testament expounds their doctrinal and practical implications. To be saved is to be saved by Christ; to be a Christian is to be in Christ; to have forgiveness is to be forgiven by Christ; to have hope is to have hope in Christ; in short, for the Christian “to live is Christ” (Phil. 1:21).
Christ further identifies Himself in His own words in verse 16. But before doing so He tells John, “I, Jesus, have sent My angel to testify to you.” Though angels communicated the Apocalypse to John (v. 6; 1:1; 17:1, 7; 21:9), its source was Jesus. The expression “I, Jesus” appears only here in the Bible. It establishes that this final invitation in Scripture is not a human invitation, but a divine call issued personally to sinners by the Lord Jesus Christ. The Apocalypse is addressed to the churches (1:11), but though it is written to believers (1:1), they are to proclaim it to the entire world (cf. 22:10).
Then, in an astounding, seemingly paradoxical statement, Jesus declares Himself to be both the root (ancestor) and the descendant of David. That phrase sums up the biblical teaching on Christ’s two natures; only the God-man can be both David’s ancestor and his descendant. In His deity, Christ is David’s root (cf. Mark 12:35–37); in His humanity, He is David’s descendant (2 Sam. 7:12–16; Ps. 132:11–12; Matt. 1:1; Rom. 1:3; 2 Tim. 2:8).
Finally, Jesus describes Himself as “the bright morning star.” To call someone a star was in biblical times (as it is today) to exalt him (cf. Dan. 12:3). In extrabiblical Jewish writings, the coming Messiah was called a star (Robert H. Mounce, The Book of Revelation, The New International Commentary on the New Testament [Grand Rapids: Eerdmans, 1977], 395). Though Balaam was a greedy prophet for hire, God nevertheless used him to make an accurate prediction of the coming Messiah: “A star shall come forth from Jacob, a scepter shall rise from Israel” (Num. 24:17). Peter wrote of the time when “the day dawns and the morning star arises in your hearts” (2 Pet. 1:19). Jesus promised to give the overcomers at Thyatira the “morning star” (2:28)—that is, Himself. As the morning star heralds the arrival of the day, so Jesus’ coming will herald the end of the darkness of man’s night, and the glorious dawn of His kingdom. Christ is the “Light of the world” (John 8:12) who calls sinners to drink of the water of life. And to those who heed that call He promises, “Come to Me, all who are weary and heavy-laden, and I will give you rest” (Matt. 11:28); and “The one who comes to Me I will certainly not cast out” (John 6:37).
 MacArthur, J. F., Jr. (2000). Revelation 12–22 (pp. 306–307). Chicago: Moody Press.