This is not just a problem to address atheists. It also encourages religious people to respect other people's religion and customs. Some people fast. Some people don't eat pork. Some people don't eat cow meat. Some people choose to wear skull caps. Some people have red spots on their forehead. Some wear a cross on a necklace. It's things like that which people should learn why it's important to those people, and to not be ignorant as to sneer at them for those choices. RE encourages a more tolerant and respectful society.
First of all I am a non religious person and believe in freedom of religion to all. Religions should be learned about but not Forced on someone. It should be a class that students choose to take and have options to choose from such religion in regions. This will help teach kids about acceptance and other cultures.
Science and logic beats a lot of religions. For example, evolution DID happen, and all life we know was NOT created in 6 days (or a few days). It would be ILLEGAL to teach religion in public schools. The only exception is private schools which enhance the child's religion (People who believe Hinduism learn facts about Hinduism, and etc). Teaching religions to people who don't practice that religion is unfair and should be illegal (Forced conversion of religion (ISIS which should be stopped from being extreme))
There is absolutely no place for religion in public schools. There is a separation between church and state in this country and it would be against our own constitution to do so. Not everyone in this country is the same religion and some have no religion at all. It would be unfair and dishonest to teach something with no evidence as fact.