Thousands of churches kicked off a national youth initiative Sunday that has been endorsed by some of the world's top Christian artists.

Pray21, a new push by Christian Endeavour International, is encouraging teens and adults to pray together for 21 days this month to build stronger faith in a younger generation that is often doubted.

"There's a generation of young people waiting for someone to believe in God's call on their life. Let's not let doubt be our first response!" said Timothy Eldred, CEO of Christian Endeavour International.

Churches in over 40 countries have signed up to participate in Pray21 and US leaders including well-known pastor and author Tony Campolo, Jim Daly of Focus on the Family, and Dr Jack Hayford of Church on the Way have joined in to support the movement.

More recently, popular Christian musicians Mercy Me, Sonic Flood, Building 429 and Tammy Trent added their support.

"Have you taken the time to pray for a teen in your church?" Trent posed. "I'd encourage you to do that today. God has honestly done amazing things in my life through prayer and encouragement, especially in the adults in my life in church growing up. They not only cared enough to pray for me, but with me."

With the majority of young adults dropping out of the church, according to recent studies, Pray21 calls participants not to just pray for youth, but to pray with them.

A 2006 Barna Group study revealed that most twentysomethings (six out of 10) disengage from active participation in the Christian faith during their young adult years. Last month, a LifeWay Research study found that two-thirds of young adults who attend church stopped attending regularly for at least a year between the ages of 18 and 22.

With a major transition out of high school to college or work, young adults reshuffle priorities, often leaving out the church from the top of the list, as Ed Stetzer, director of LifeWay Research, indicated in the report.

"Like many of you I look around at student culture sometimes and it's a little discouraging," said Geoff Moore, a longtime Salvation Army advocate. "It's discouraging to see all the battles and struggles and the hard times some of the students have."

Nevertheless, Eldred reminds adults that it's time to trust the young people.

"Until the church learns to trust more than we lean on our own understanding, we will continue to lose the battle for this generation," he stated.

"Believing is putting your faith in to action. You can't say I trust you and never make room for them to take ownership in or be agents of change.

"This is true in the church, in the nation, and in the world," said Eldred.

Through the 21 days of prayer, Eldred hopes belief is born to accept young people's mission to transform the world.

"Youth ministry tends to be what we do for and to young people. The result of Pray21 is what young people do. Significant difference," he added.

On the web: Pray21 resources at www.pray21.org