Lovett H. Weems has written an interesting article in a September 22, 2010 article in The Christian Century. He shows that worship attendance among mainline Protestant churches increased slightly in the 1990's, but has had a steep decline in the first part of the 21st century.
David A. Roozen, reporting on the findings of the 2008 Faith Communities Today survey of American congregations of all types, points out that the "erosion of vitality" holds not only for "oldline" Protestants but also for evangelical Protestants, Catholics, Orthodox and "other world religions." The new century has brought a "retreat for America's congregations," according to Roozen. Churches averaging 350 or more have declined steadily since 2001. However, churches averaging over 1000 have continued to increased in worship attendance.
What are the reasons for the drop?
One possibility is less frequency in worship attendance. Some studies show that people consider as "regular" worship attendance in a local church is changing. The percentage saying they attend once a week has steadily gone down.
Another reason is that the mainline congregations have a disproportionately high number of people over 65. For health reasons, they may be attending church less often. Further, these churches have not reached the younger generation.
A third reason is that the 25-34 age group has the highest proportion of persons responding "no religion." Studies indicate that this will be difficult to change.
Curiously missing are reflections on theology and social positions of these denominations. I have no studies to which to refer. I do, however, have a suspicion in these areas.
I am also suspicious that authors like Richard Dawkins, and many others, may have had their influence in terms of undermining "religion." Their basic position, like that of Freud, is that religion is an expression of narcissism and superstition, and thus needs to be eliminated, much like belief in the tooth fairy.
What do you think might be some of the reasons for the decline?