religious activities varies from decade to decade and from century to century. In the end, it means little.
You are absolutely correct in that it ebbs and flows. However, you are wrong when you say it matters for little. It's hugely consequential.
In America, you had the Great Awakenings. The Second Awakening, lasting for several decades in the early 1800s, birthed a bunch of new religions: Adventism, Dispensationalism, and the Latter Day Saints among others. There was also a Third Awakening, and then some smaller level spikes.
In the Middle East it is the same - where in the early 20th century you had powerful secularist movements driven by Pan-Arabists and modernizers - but then later a great religious awakening again, driven by the early Muslim Brotherhood.
In Russia, you had an explosion of religiosity starting in the late 1990s. Mormons, Jehovah's Witnesses, all types of Baptists, and others were making hay in Russia. Thousands of Orthodox churches were restored.
The American Great Awakening was a reaction to the rationalism and deism that dominated the American Enlightenment through the Revolutionary period.
The Arab religious awakening was a reaction to the corruption and incompetence of the nationalists and modernizers, which failed to produce the promised results.
The Russian awakening was the filling of a spiritual vacuum in a collapsing state.
Religion has an annoying tendency to come back, just when you thought it was dead.
