Revelation 1:7-8

7Behold, He is coming with the clouds, and every eye will see Him, even those who pierced Him; and all the tribes (nations) of the earth will mourn over Him [realizing their sin and guilt, and anticipating the coming wrath]. So it is to be. Amen.

8“I am the Alpha and the Omega [the Beginning and the End],” says the Lord God, “Who is [existing forever] and Who was [continually existing in the past] and Who is to come, the Almighty [the Omnipotent, the Ruler of all].”