Everyone has an opinion about why Millennials are leaving the church. It’s a controversial topic, one that Barna Group’s researchers have been examining for a decade. The topic was reignited this summer when blogger and author Rachel Held Evans wrote a piece about why Millennials leave church. Her editorial struck a nerve, sparking response pieces all across the web and generating more than 100,000 social media reactions in the first week alone.

Yet whatever one’s personal view of the reasons behind Millennials staying or going, one thing is clear: the relationship between Millennials and the Church is shifting. Barna Group’s researchers have been examining Millennials’ faith development since the generation was in its teen years—that is, for about a decade. During that time, the firm has conducted 27,140 interviews with members of the Millennial generation in more than 200 studies.

And while Barna Group’s research has previously highlighted what’s not working to keep Millennials at church, the research also illuminates what is working—and what churches can do to engage these young adults.

The Harsh Realities of Millennial Faith

But first, the concerns of Millennials leaving the Church must be understood.