Revelation 22:13

I am the Alpha and the Omega, the Beginning and the End
Alpha (Α) and omega (Ω) are the first and last letters of the Greek alphabet. Thus, Jesus is the first and the last (below). Jesus also used this unique title of God in the opening chapter of this book. The Father takes it to Himself in the previous chapter (Rev. Rev. 21:6+). See commentary on Revelation 1:8.

the First and the Last
In the OT, this title is uniquely God’s (Isa. Isa. 41:4; Isa. 43:10; Isa. 44:6; Isa. 48:12). Jesus applied it to Himself when He told John to write what he saw and send it to the Seven Churches of Asia (Rev. Rev. 1:11+). Jesus is eternal (John John 1:1; Isa. Isa. 9:6; Mic. Mic. 5:2; John John 8:58; John 17:5; Col. Col. 1:17; Heb. Heb. 13:8). As we’ve seen in many different ways throughout this book, Jesus is God! See commentary on Revelation 1:11.