Why do so many young adults (18 to 22) leave the church, and what will it take to bring them back? This important question is examined and duly answered in Essential Church?, a follow-up to Thom S. Rainer’s best-selling Simple Church cowritten this time with his son, research expert Sam Rainer.

The book is based on a study of one-thousand so-called "church dropouts" who were interviewed about why they left. Their answers are quite surprising, having less to do with "losing their religion" and more about the desire for a community that isn’t made stale by simply maintaining the status quo.

In turn, the Rainers offer churches four concrete solutions toward making their worship community an essential part these young people’s lives again:

 Simplify - develop a clear structure and process for making disciples.

Deepen - provide strong biblical teaching and preaching.

Expect - let members know the need for commitment to the congregation.

Multiply - emphasize evangelism, outward focus, and starting new churches.