Americans' religious affiliations and degree of religious adherence tend to follow a generational step-down pattern. For instance, in my grandparents' day, bot

Americans' religious affiliations and degree of religious adherence tend to follow a generational step-down pattern. For instance, in my grandparents' day, both religious affiliation and religious adherence were relatively high. In Philly, where my mom grew up, Catholic schools were practically overflowing, and parents expected that the school would supplement and support the religious upbringing they were receiving at home. Then in the next generation, there was a shift. Religious affiliation remained relatively high, but religious adherence and attendance began to decrease. Those Catholic schools continued to bring in students, but there was a marked difference; parents who were not particular devout themselves expected that the school would replace and make up for the religious instruction that many of the kids were not receiving at home. These people might still have identified themselves as Catholic, but they weren't really actively practicing their faith. Nowadays, Catholic schools are largely on life support, because the decrease in religious affiliation that was precipitated by the decrease in adherence/attendance has now cut down enrollment to a much smaller number of families who either have high devotion or who have low devotion but see the schools as better than the public alternatives. Parents who in the previous generation might have sent their kids to Catholic school to replace the religious instruction they weren't getting at home have instead decided to disaffiliate and not give their kids outsourced religious instruction. Whereas in previous generations, they might have continued to identify as Catholic even though they were inactive, in this generation it's much more common to just shed the identity. Obviously, I'm just painting a small part of the picture, of Catholicism in the mid-Atlantic region. Many other parts of the country with other religious makeups have followed different patterns. But I think we can basically predict what the religious landscape is going to be like over the next generation or two by following this step-down pattern. (This assumes that religiosity will continue getting weaker, which is not necessarily a sure thing. Religious revivals have been relatively common throughout history.)