One? Two? Many?
There is only one God, YHWH. But there are many 'gods' - And in that, I am pointing to 'powers and principalities' wherein the real war lies. Apollyon (Apollo) is not God, but he claims to be. Likewise, Allah is not God, though He claims to be.
Where there is a prophet, claiming to represent a god, that is something to be taken very seriously.