The American Heritage Dictionary of the English Language, Fourth Edition, as one can read it on The Free Dictionary, says:
alpha and omega, noun:
1. The first and the last: "I am Alpha and Omega, the beginning and the ending, saith the Lord" (Revelation 1:8).
2. The most important part.
It is a noun that resembles to the Italian, literally, "from A to Z", an expression used to say that a certain thing is complete. "The report is complete from A to Z" means that it doesn't lack anything, and probably it is the same in English.
After reading the above definition, in the light of what I said, I began wondering if the two expressions, "tha alpha and the omega" and "from A to Z", mean the same thing.
1) "I was forced to read the alpha and omega of 'The Principia Mathematica', written by Alfred North Whitehead"
2) "I was forced to read, from A to Z, 'The Principia Mathematica', written by Alfred North Whitehead"
Can anybody explain the difference in meaning between 1) and 2)?