Alpha and Omega
ALPHA AND OMEGA ăl’ fə, ō mĕg ə (Α καἱ Ω).
The first and last letters of the Greek alphabet, alpha being equivalent to our letter a and omega (literally, great O) to our long o as in no. The first and last letters of the Hebrew alphabet are א and ת and these were used by the ancient Jews to mean “from first to last” or “from beginning to end,” as one might say, “from A to Z.” This Jewish usage probably explains the similar usage of alpha and omega in the New Testament.
Usage in the New Testament