As I said before, it is a complex topic and there are many difficult questions to answer. But, I think it's more helpful to understand religions as entire ways of life rather than simple affirmations of belief. My observation is that people today define much of their identity by what they say and not necessarily by how they act or what they value. Whether that is what they truly are is again, a complex question.

With Christianity, for example, the history there is immensely complicated. There are perhaps an infinite number of interpretations of Jesus' teachings and actions, many of which place far less focus on belief than on works (actions.) Other groups don't care whatsoever what any organized church says and base their beliefs and actions on traditions or on the Bible itself. Paul, the Catholic Church, Martin Luther, and innumerable others have shaped "Christianity" over the last two thousand years, so to say that the contemporary American definition is all that counts is a bit historically ignorant.

Beyond that, it's also unclear precisely what "supernatural" means in this context.

In sum: it's complicated.