Revelation 1:8

τὸ ἄλφα καὶ τὸ ὦ. The first and last letters of the Greek alphabet used, as in Rabbinical proverbs the first and last letters of the Hebrew alphabet were, as symbols of “the beginning and the end.” These latter words (ἀρχὴ καὶ τέλος) are not here a part of the genuine text; they come from Revelation 22:13. The word “Omega” (like “Omicron,” “Epsilon,” “Upsilon,”) is a mediaeval barbarism; but it is a convenient one, and it has secured a firm place in our language by the English rendering of this passage.

κύριος ὁ θεὸς κ.τ.λ. The group of titles represents “the Lord Jehovah the God of Hosts,” a combination of Hosea 12:5 and Amos 9:5. The word we render “Almighty” (perhaps rather meaning “of all might”) does not correspond to the word “Shaddai” which we translate “Almighty” in the Old Testament. The LXX. evade this word in the Pentateuch, even in Exodus 6:8 and parallel passages; it is never translated by παντοκράτωρ except in the Book of Job. Elsewhere in the Septuagint παντοκράτωρ always stands for “Sabaoth.” So in the Athanasian Creed, “Almighty” is coupled with the Divine names “God” and “Lord,” not with the Divine attributes “eternal, incomprehensible, uncreated.”