Turn to me and be saved,
all the ends of the earth!
For I am God, and there is no other.
via Passage: Isaiah 45:22 (ESV Bible Online).
God is telling the Gentiles to
A. Stop breaking the First Commandment of the Decalogue.
B. Trust in the true God alone for salvation
C. Not sure but it can’t be both A and B.
D. Both A and B.
If you hesitate to say D, I think you are in the grip of some very unbiblical teaching. I don’t think it is confessionally Reformed thinking either.