In short, my characters are in a position where they're interacting with aspects of the gods in a mysterious underworld that they have to puzzle their way out of.
Of course, things would be easy if they could just ask the gods for guidance and get a clear answer, and one of the characters is a decently high-level cleric of the chief deity. But I don't want the gods to give them easy answers. In fact, the gods want the heroes to stay here, not to leave.
So is it possible for a god to directly lie to their clerics to further their own cause? Can these aspects of the deities give knowingly bad information to the PCs in furtherance of the story?
Of course, Rule Zero is that if the DM says it, it's true; but I'm concerned about the effect of lying gods on other aspects of the setting. If the gods can lie, can clerics trust the answers of their augury spells or divine guidance spells?
This is in a homemade world, so I can make up the rules, of course; in general, though, it seems like a step that needs to be carefully considered.