Revelation 1:8

8IἘγώamεἰμιtheτὸAlphaἌλφαandκαὶtheτὸOmegaὮ,saysλέγειLordκύριος,ὁGodθεός,the [One]ὁbeingὢνandκαὶwhoὁwasἦνandκαὶwhoὁis comingἐρχόμενος,theὁAlmightyπαντοκράτωρ.

“I am the Alpha and the Omega,” says the Lord God, the One who is and who was and who is coming, the Almighty.