Deuteronomy 6:4

‘I am Yahweh your God who brought you out of the land of Egypt, out of the house of slavery.

“Indeed, He loves the people; All Your holy ones are in Your hand, And they followed in Your steps; Everyone is bearing up Your words.

And they taught in Judah, having the book of the law of Yahweh with them; and they went throughout all the cities of Judah and taught among the people.

“You alone are Yahweh. You have made the heavens, The heaven of heavens with all their host, The earth and all that is on it, The seas and all that is in them. You give life to all of them And the heavenly host bows down to You.

For He established a testimony in Jacob And set a law in Israel, Which He commanded our fathers That they should teach them to their children,

For You are great and do wondrous deeds; You alone are God.

And Yahweh will be king over all the earth; in that day Yahweh will be the only one, and His name one.

Jesus answered, “The foremost is, ‘Hear, O Israel! The Lord our God is one Lord;

since indeed God, who will justify the circumcised by faith and the uncircumcised through that faith, is one.

Therefore, concerning the eating of things sacrificed to idols, we know that an idol is nothing in the world, and that there is no God but one.

yet for us there is one God, the Father, from whom are all things and we exist for Him, and one Lord, Jesus Christ, by whom are all things, and we exist through Him.

You believe that God is one. You do well; the demons also believe, and shudder.