What are the Tensions and controversies associated with freedom of religion?

Question

How has it been protected? Where do we "Draw the line?" Wht have been the historical disagreements?

Answer 1

The First Amendment defines two aspects of religious freedom. The government cannot establish any religion (that is, cannot single out any any faith, no matter how popular, as the nation's official religion with special privileges denied to other faiths) and cannot prohibit the free exercise of religion (that is, cannot stop people from practicing any faith, no matter how unpopular).

The tensions and controversies you mention arise from disagreements about how to balance the non-establishment and free-exercise aspects of religious freedom.