Yes, teaching religion as a simple myth is fine. It is basically like a child reading a story book or some other fairy tale. If kids are taught that Jesus, or Allah are actually real and he or she is coming one day to exact judgement on humanity then they grow up being radical in belief in the name of their God which then leads to radicalism and thus potentially strapping bombs to one self to send a message to the world. No religion should be taught as a simple myth to avoid this ridiculous behavior among people who think their God is the only God. There are thousands of beliefs and billions of people. Your God that God his God her God it's all the same, people thinking their right in their own minds and coming up with their own form of reality. Humans really are the most peculiar species on this space rock we call earth. Gods are a human construct used to control others and bind them to their will. If you cannot see this or disagree with this notion, your probably a religious person, therefore there is no reason to go on talking as you people or whatever you call yourselves are unreasonable to a fault. You all deserve to be controlled and brainwashed by your pastors. "SHEEP"
About the only difference between a religion and mythology is the current number of people who believe it. What we call mythology today are religions of the past that few if any still follow.
When it comes to public schools that the state funds, religion can not be taught because of the 1st Amendment forbids it.
The question as phrased is too vague to lend itself to a simple answer. Some religions are mythological and if taught properly as a fact of history, they would be taught as mythological. The same is not the case with religions which are not mythological, but based on the true worship of the true God. Teaching that as mythological would be teaching that a lie is true, and that the truth is a lie. That should never be the goal of education, which by definition should be a source of knowledge, not indoctrination to error.