Saddleback Church is an evangelical Christian megachurch located in Lake Forest, California, situated in southern Orange County, affiliated with the Southern Baptist Convention.
 The church was founded in 1980 by Pastor Rick Warren.
 Weekly church attendance averages over 20,000 people, currently making it the fifth-largest church in the United States by attendance (this ranking includes multi-site churches).
Rock Church is an evangelical megachurch located in San Diego, California, with five campuses located in Point Loma, San Marcos, El Cajon, San Ysidro, and City Heights.
 Miles McPherson, a former NFL player, has served as senior pastor since he founded the church in 2000.
 With an average weekly attendance of more than 19,000 as of January 2016 at four weekly services at each campus, as well as live online streaming, the Rock is one of the largest churches in San Diego.
The Meeting House is an Anabaptist church located in the Toronto suburb of Oakville, Ontario.
 It was founded in 1985 by Craig and Laura Sider, and was originally known as "Upper Oaks Community Church".
 With a consistent average weekly attendance of 4,400, it is ranked by the Hartford Institute of Religion as fourth among large churches (sometimes called megachurches) in Canada.
 Teaching (sermons) produced on the church's main Oakville campus is either simulcast or sent out on a one-week delay to nineteen satellite Ontario satellite locations, most of which meet in cinemas.
 The Meeting House is part of a denomination called the Be in Christ.
The Purpose Driven Life (2002) is a devotional book written by Christian author Rick Warren and published by Zondervan.
 The book topped the "Wall Street Journal" best seller charts as well as "Publishers Weekly" charts with over 30 million copies sold by 2007.
 "The Purpose Driven Life" was also on the New York Times Bestseller List for over 90 weeks.
Frontline was the young adult ministry of McLean Bible Church, a non-denominational evangelical Christian church with campuses throughout the Washington, DC metropolitan area.
 Frontline was started in 1994 and has an average weekly attendance of over 2500 between its multiple campuses.
 John McGowan is the current Director and Teaching Pastor for Frontline.
 In early 2011 John stepped up for Todd Phillips, Frontline's previous Teaching Pastor.
 Todd Phillips now teaches at Lake Pointe Church; a multi-site church outside of Dallas, Texas.
Richard Duane "Rick" Warren (born January 28, 1954) is an American evangelical Christian pastor and author.
 He is the founder and senior pastor of Saddleback Church, an evangelical megachurch in Lake Forest, California, that is the eighth-largest church in the United States (including multi-site churches).
 He is also a bestselling author of many Christian books, including his guide to church ministry and evangelism, "The Purpose Driven Church", which has spawned a series of conferences on Christian ministry and evangelism.
 He is perhaps best known for the subsequent book "The Purpose Driven Life" which has sold more than 30 million copies, making Warren a "New York Times bestselling author.
Fairfax Community Church (Fairfax.cc) is an evangelical congregation located in Fairfax County, Virginia.
 The church is affiliated with the Church of God, Anderson, Indiana.
 By membership, the church is classified as a megachurch, with an average weekly attendance in 2012 of 2,158.
 It served as a satellite site for the 2007-2010 Willow Creek Association Global Leadership Summit.
The Purpose Driven Church (1995) is a book written by Rick Warren, founder and senior pastor of Saddleback Church in Lake Forest, California, United States.
 It was published in 1995, subtitled ""Growth Without Compromising Your Message & Mission"."
 In a May 2005 survey of American pastors and ministers conducted by George Barna, "The Purpose Driven Church" was voted as the second book most influential on their lives and ministries, behind "The Purpose Driven Life", a subsequent book by Rick Warren.
Mars Hill Church was a Christian megachurch, founded by Mark Driscoll, Lief Moi, and Mike Gunn.
 It was a multi-site church based in Seattle, Washington and grew from a home Bible study to 15 locations in 5 U.S. states.
 Services were offered at its 15 locations; the church also podcast content of weekend services, and of conferences, on the Internet with more than 260,000 sermon views online every week.
 In 2013, Mars Hill had a membership of 6,489 and average weekly attendance of 12,329.
 Due to controversy in 2014 involving founding pastor Mark Driscoll, the attendance dropped to 8,0009,000 people per week.
 The church merged three of its Seattle locations and cut 3040% of its staff to deal with decreases in giving.
 At the end of September, 2014, an investigation by the church elders found "bullying" and "patterns of persistent sinful behavior" by Driscoll.
 The church elders crafted a "restoration" plan to help Driscoll and save the church.
 Instead, Driscoll declined the restoration plan and resigned.
 On October 31, 2014, lead pastor Dave Bruskas announced plans to dissolve the church's 13 remaining campuses into autonomous entities, with the option of continuing, merging with other congregations, or disbanding, effective January 1, 2015.
Peoples Church is a megachurch in Fresno, California, USA with an average weekly attendance of 3,707 people in 2016, and an average weekly online viewership of 2,420 people in 2016.
 The church is led by Pastor Dale Oquist.
 The church campus includes Fresno Christian High School, a private school attended by students in grades K-12.

Question: What is the average weekly attendance at the church founded by the author of The Purpose Driven Life ?
Answer: over 20,000