First set of verses:
“I am the Alpha and the Omega,” says the Lord God, “who is, and who was, and who is to come, the Almighty.” (Revelation 1:8)
“When I saw him, I fell at his feet as though dead. Then he placed his right hand on me and said: “Do not be afraid. I am the First and the Last.” (Revelation 1:17)
Second set of verses:
12“Look, I am coming soon! My reward is with me, and I will give to each person according to what they have done. 13I am the Alpha and the Omega, the First and the Last, the Beginning and the End.
14“Blessed are those who wash their robes, that they may have the right to the tree of life and may go through the gates into the city. 15Outside are the dogs, those who practice magic arts, the sexually immoral, the murderers, the idolaters and everyone who loves and practices falsehood.
16“I, Jesus, have sent my angel to give you this testimony for the churches. I am the Root and the Offspring of David, and the bright Morning Star.” (Revelation 22:12 – 16)
It’s Lord Jesus Christ (Rev 22:16)= who says “I am coming soon” (Rev 22:12) = I am the First and the Last (Revelation 1:17 & Rev 22:13) = I am the Alpha and Omega (Rev 22:13 and Rev 1:8) = the Almighty (Rev 1:8)
It’s simple (literally)
See the link?