A und O

Etymology
From. From the biblical book of Revelation, verses 1:8 and 22:13. The expression refers to God as “the beginning and the end”, the letter omega being the last of the Greek alphabet.

Noun

 * 1)  that which is important; that which matters; a sine qua non
 * 2)  alpha and omega
 * 1)  alpha and omega

Usage notes

 * The biblical expression is not usually translated with these words now. For example, in the Einheitsübersetzung verse 22:13 runs: “Ich bin das Alpha und das Omega, der Erste und der Letzte, der Anfang und das Ende.”