Its meaning is found in the fact that alpha (?) and omega (?) are respectively the first and last letters of the Classical (Ionic) Greek alphabet. This would be similar to referring to someone in English as the “A and Z”. Thus, twice when the title appears it is further clarified with the additional title “the beginning and the end”
Reference Text:
Isaiah 44:6
6Thus says the Lord, the King of Israel and his Redeemer, the Lord of hosts: I am the First and I am the Last; besides Me there is no God.
Isaiah 48:12
12Listen to Me, O Jacob, and Israel, My called [ones]: I am He; I am the First, I also am the Last.
My Commentary:
Talk about power and might when all things Begin and End with you. There is just nothing else to say when you look around and nature and say what, who, how can anything make all this I go back to “The Alpha and the Omega”.