I have long heard "Religion is just a metaphor" (mostly from fans of Joseph Campbell). I have never been happy with it as an answer. So I thought I would try some thinking with my fingers to see if I can clarify my objections. As per usual the Wikipedia gives us a great jumping off point:
...This seems to be the sense of metaphor we are concerned with.
A root metaphor is the underlying association that shapes an individual's understanding of a situation. Examples would be understanding life as a dangerous journey, seeing life as a hard test, or thinking of life as a good party. A root metaphor is different from the previous types of metaphor in that it is not necessarily an explicit device in language, but a fundamental, often unconscious, assumption.
Religion provides one common source of root metaphors, since birth, marriage, death and other universal life experiences can convey a very different meaning to different people, based on their level or type of religious conditioning or otherwise. For example, some religions see life as a single arrow pointing toward a future endpoint. Others see it as part of an endlessly repeating cycle.
As I see it calling religion a metaphor is another way to obscure the quest for knowledge and understanding.
"Jung says religion is a defense against the experience of god. I say our religions are." -- Joseph Campbell - Mythic ReflectionsThe problem is not getting religion out of the way so we can experience god. The problem is assuming there is a god to be experienced. The best plan is to solve the mysteries not just experience them.
However, the multiplicity of gods and religions is a very good teaching point. It does show that the ideas get confused somewhere. The error is to assume we are confused about something that is really there. Lots of people once thought disease was caused by spirits, now we know better. Dressing up the god of the gaps in lots of different metaphors does not make the idea more plausible.
Still a little rough, but it is late (not like anyone reads my stuff :-)