You left out the part about the sublime. The value of art isn't entirely subjective, since the brain is part of a much larger world. That asymmetry generates the mystical sense of the sublime and the wonder that anything should exist at all.
Sensitive artists tend to be marginalized so that they fall into positions of being social critics; their judgments against self-destructive conventions needn't be subjective either.
The problem with religion as a source of artistic inspiration is that it's based on misunderstandings and frauds. The sublime and the numinous as well as the sensitivity of social outsiders are real. Religious myths are fictions. Fictions can tell the truth in different ways, but that's only if they're read as good stories, not as creeds and dogmas.