The first letter in almost all alphabets. In Hebrew, it is called aleph, in Greek, alpha, the last letter in the Greek alphabet being omega. Both the Hebrews and Greeks used their letters as numerals; and hence A (aleph or alpha) denoted one, or the first. So our Lord says, "I am Alpha and Omega, the beginning and the end, the first and the last;" thus declaring his eternity and that he is the cause and end of all things, Revelation 1:8,11 21:6 22:13 Isaiah 44:6 48:12 Colossians 1:15-18 .