E.g.
>Deut. 6:4. Hear, O Israel: The LORD our God is one LORD . Isa. 44:6. Thus
saith the L ORD the King of Israel, and his redeemer the LORD of hosts; I am the first,
and I am the last; and beside me there is no God. Isa. 45:21–22. Tell ye, and bring
them near; yea, let them take counsel together: who hath declared this from ancient
time? who hath told it from that time? have not I the L ORD? and there is no God else
beside me; a just God and a Saviour; there is none beside me. Look unto me, and be ye
saved, all the ends of the earth: for I am God, and there is none else. 1 Cor. 8:4–6. As
concerning therefore the eating of those things that are offered in sacrifice unto idols,
we know that an idol is nothing in the world, and that there is none other God but one.
For though there be that are called gods, whether in heaven or in earth, (as there be
gods many, and lords many,) but to us there is but one God, the Father, of whom are all
things, and we in him; and one Lord Jesus Christ, by whom are all things, and we by
him.
From [WSC #5](https://opc.org/documents/SCLayout.pdf) proof texts