On this I agree with @Paul Farquhar. A setting in which the divine is, per se, good, may still have opposition. LotR gives a fantasy example.
JRRT has no evil gods. It's a monotheistic setting.
Morgoth is a fallen angel. He has no power to create. He can corrupt, lure and dominate. It seems likely - in D&D terms - that he can cast spells, but not ones that create or conjure forth forces or beings. We know, for instance, that Melkor could not himself make the Silmarils. When Sauron makes the ring, he has to power it with his own essence (he can't create new power). The Black Captain can destroy things by speaking words of power and terror - but I don't think he can create.
IIRC I think the silmarillion refers to the Valar as gods on at least one occasion