This puzzle is very simple to me, I'm sorry if it's complicated to other people but thats not my problem. This puzzle is meant to twist the boundaries of logic, and make you think of multiple ways to ask questions that give the correct answer. Either way, this puzzle is completely up to chance, so there is no 100% way to get only one right answer.
Edit: And as a explanation to your rather stupid statement, you can assume the answers, up until you find out who the truthful god is, then you can ask the question. So in reality, you must assume which answer means what so you can find out which god is which. So you can find out the right answer. There is no real way to solve this without assuming something for however short a time.