When Baby Boomers were born, the Protestant landscape of America was dominated by the six major mainline denominations. (Those bodies are typically considered to be the American Baptist Churches in the USA; the Episcopal Church; the Evangelical Lutheran Church in America; the Presbyterian Church (USA); the United Church of Christ; and the United Methodist Church.)

Since the 1950s, however, mainline churches have fallen on hard times, declining from more than 80,000 churches to about 72,000 today. The growth among evangelical and Pentecostal churches since the 1950s, combined with the shrinking of the mainline sector, has diminished mainline churches to just one-fifth of all Protestant congregations today. In the past fifty years, mainline church membership dropped by more than one-quarter to roughly 20 million people. Adult church attendance indicates that only 15% of all American adults associate with a mainline church these days.

A new report issued by The Barna Group focuses upon changes in the mainline churches during the past decade. The report examines shifts in both the adults who attend those churches and the pastors who lead them.

Over the course of the past decade, the number of adults who attend a mainline church on any given weekend has remained relatively stable, ranging from 89 to 100. The current median is 99 adults. One reason why that average has remained steady has been the population growth of the United States, with the mainline churches attracting just enough newcomers to maintain attendance levels that are similar to the years when the nation’s population was considerably smaller.