Bible Verses About Unity of God: God himself

Thus saith the Lord the king of Israel, and his redeemer the Lord of hosts: I am the first, and I am the last, and besides me there is no God.

Fear ye not, neither be ye troubled from that time I have made thee to hear, and have declared: you are my witnesses. Is there a God besides me, a maker, whom I have not known?

For thus saith the Lord that created the heavens, God himself that formed the earth, and made it, the very maker thereof: he did not create it in vain: he formed it to be inhabited. I am the Lord, and there is no other.

Tell ye, and come, and consult together: who hath declared this from the beginning, who hath foretold this from that time? Have not I the Lord, and there is no God else besides me? A just God and a saviour, there is none besides me.