"I am THE ALPHA and THE OMEGA,
This is one of the names of Jesus Christ (Revelation 1:8 and Revelation 21:6). We recognize Alpha and Omega as the first and last letter respectively in the Greek alphabet. Now, alphabets in occidental languages are used to construct words and sentences. That is, they are used to communicate. Colossians 1:15-16-23 indicates that Christ was at the creation of the original earth. It is no accident that God SPOKE the creation (Genesis 1:3-6-9-11-14-20-24-26-29-31) into being. In a similar manner, it is no accident that this Revelation was communicated to John (Revelation 1:1). In fact, the second to the last verse in this Revelation is Jesus SAYING, "Yes, I am coming quickly."
THE FIRST and THE LAST,
John's first encounter with Jesus in this Revelation finds Jesus touching John with His right hand, the hand of authority, and comforting John with these same words (Revelation 1:17). Just as THE ALPHA and THE OMEGA was an alphabetic ordering, THE FIRST and THE LAST is a numeric ordering. When Jesus talked about the difficulty of making Him the master of our lives, he often ended the discussion with words referring that the first will be last and the last will be first (Mark 10:17-31, Matthew 20:1-16, and Luke 13:22-30). Humans have an inborn need apparently to know where they fit within society. But here Jesus is saying that He fits next to each of us who are residents of the new Jerusalem (Revelation 21:2-3,9-10). He is the bridegroom to each of us, THE FIRST and THE LAST.
THE BEGINNING and THE END."
Here we are presented with a conceptual difficulty. Jesus as part of God and equal to God is forever. That is, He has no BEGINNING and no END. So this phrase must refer specifically to Jesus Christ as the Son of Man. He assumed the character and nature of man (Philippians 2:1-11). He had a BEGINNING (Luke 2) as man, and He had an END as man (Luke 23:44-49). In between His human BEGINNING and END, He was tempted in every way as mankind is or has been (Hebrews 2:14-18 and Hebrews 4:14-16). Furthermore, He overcame His human ending and conquered DEATH (Revelation 1:18).
We can say that Jesus communicates in God-speak (John 14:1-10-11), He occupies all from THE FIRST to/through THE LAST, and He experienced all of human life. Thus He, as revealed in this book, can redeem the earth (Revelation 5:5) and provide our forever home (John 14:1-2-11).