Alpha, the first letter of the Greek alphabet, as Omega is the last.
These letters occur in the text of (Rev 1:8, Rev 1:11; Rev 21:6; Rev 22:13), and are represented by "Alpha" and "Omega" respectively [omitted in R.V.] (Rev 1:11). They mean "the first and last." (Hbr 12:2; Isa 41:4; Isa 44:6; Rev 1:11, Rev 1:17; Rev 2:8.) In the symbols of the early Christian Church these two letters are frequently combined with the cross or with Christ's monogram to denote his divinity.