Are Americans becoming less religious? It depends on what you mean by “religious.”

Polls certainly indicate a decline in religious affiliation, practice and belief. Just a couple of decades ago, about 95 percent of Americans reported belonging to a religious group. This number is now around 75 percent. And far fewer are actively religious: The percentage of regular churchgoers may be as low as 15 to 20 percent. As for religious belief, the Pew Research Center found that from 2007 to 2014 the percentage of Americans who reported being absolutely confident God exists dropped from 71 percent to 63 percent.

Nonetheless, there is reason to doubt the death of religion, or at least the death of what you might call the “religious mind” — our concern with existential questions and our search for meaning. A growing body of research suggests that the evidence for a decline in traditional religious belief, identity and practice does not reflect a decline in this underlying spiritual inclination.

Ask yourself: Why are people religious to begin with? One view is that religion is an ancient way of understanding and organizing the world that persists largely because societies pass it down from generation to generation. This view is related to the idea that the rise of science entails the fall of religion. It also assumes that the strength of religion is best measured by how much doctrine people accept and how observant they are.

This view, however, does not capture the fundamental nature of the religious mind — our awareness of, and need to reckon with, the transience and fragility of our existence, and how small and unimportant we seem to be in the grand scheme of things. In short: our quest for significance.