Since St. Augustine was a Christian, I don't think he fits. By "knowable" I meant something like "we can identify an action that they're more likely to regard as worship than as blasphemy, thereby making the question of whether to worship them relevant". I'm uncomfortable with my use of the action/inaction distinction there, but I'm going to leave it.

Alternate interpretation of the Marcus Aurelius quote: It illustrates how far thoughts fit ideals. Regardless of whether he took gods seriously, they were distant enough that he could make grand moral claims without worrying about living up to them.