Alpha and Omega are the first and last letters of the Greek alphabet, the language in which our New Testament was written. When used in a saying, they represent the beginning, the end, and everything in between. These letters are used by Jesus in the book of Revelation to describe His eternal qualities.
It is a clear reference to the qualities ascribed to Yahweh in the Hebrew Bible (Isaiah 44:6; 48:12). Jesus is thus characterized as the eternal, omnipotent God. First-century believers were well acquainted with the letters of the Greek alphabet and understood the symbolic meaning of the phrase, especially since a Hebrew rabbinical oral tradition dating back from the second century BCE was commonly used to denote the whole of anything. Rabbis typically used the first and last letters of the Hebrew alphabet (alef and tav) to denote this. The Mishnah (Sanhedrin 64a:4-5; Yoma 69b:6-9) also inserts the middle letter of the alphabet, mem, thus creating the word emet "truth," which it explains is "the seal of God," expressing that in God, truth dwells absolutely and fully.1
The alpha and omega appear in this vault mosaic (see picture above) from the Galla Placidia Mausoleum in Ravenna, Italy, created between 425 and 450 CE. The combination of the Christogram (i.e., the monogram of the name Christ, in Greek) and the victory wreath was a common motif in early Christian funerary art. The X and P are called the Chi-Rho which are the first two letters in the Greek word for Christ. It is one of the earliest forms of the Christogram, formed by superimposing the first two (capital) letters—chi and rho (ΧΡ)—of the Greek word ΧΡΙΣΤΟΣ (Christos) in such a way that the vertical stroke of the rho intersects the center of the chi.2
With that new understanding, let's take a look at how Jesus used this amazing phrase.
"I am the Alpha and the Omega," says the Lord God, "who is and who was, and who is to come, the Almighty" (Revelation 1:8).
No matter what challenges you face today, remember Jesus is the beginning and the end!