1:8 I am the Alpha and the Omega," says the Lord God, "who is and who was and who is to come, the Almighty."

"I am the ALPHA and the OMEGA," says the Lord God,

Here we have the first words directly spoken by God in the Revelation. They impart the meaning that God is the Beginning and the Ending; Everything created, destroyed, transformed, brought to life, and submitted to death as far as we humans are concerned is within God's purview.

This phrase implies complete occupation of the time spectrum - Matthew 28:20; but God also occupies all physical space as well - Matthew 18:20

"who is and who was and who is to come,

If this sounds familiar, it should be because it is used in verse 4 as the description of God, the Father. This phrase expands God out beyond just the Alpha and the Omega (alphabets are uniquely tied to human intellect; that is, it is our way to express concepts, ideas, feelings and emotion). This phrase says that existence of the spiritual is beyond ALL human knowledge and wisdom - Colossians 2:3.

the ALMIGHTY."

Literally, this means `the One who has His hand on everything". The ALMIGHTY is used 10 times in the New Testament. Nine of them are in the Revelation...when judgment is pending, we need to know Who is in control:

Revelation 4:8
Revelation 11:17
Revelation 15:3
Revelation 16:7
Revelation 16:14
Revelation 19:6
Revelation 19:15
Revelation 21:22