Six Reasons Young Christians Leave Church

"No single reason dominated the break-up between church and young adults. Instead, a variety of reasons emerged. Overall, the research uncovered six significant themes why nearly three out of every five young Christians (59%) disconnect either permanently or for an extended period of time from church life after age 15.

Reason #1 – Churches seem overprotective.
Reason #2 – Teens’ and twentysomethings’ experience of Christianity is shallow.
Reason #3 – Churches come across as antagonistic to science.
Reason #4 – Young Christians’ church experiences related to sexuality are often simplistic, judgmental.
Reason #5 – They wrestle with the exclusive nature of Christianity.
Reason #6 – The church feels unfriendly to those who doubt."

Barna.org, September 28, 2011

See the original article for further description of the reasons why young people leave the church.

Nearly half of British teenagers are atheists

"Nearly half of teenagers in Britain are atheists, according to a new Mori poll commissioned by the British Library.

43% of 16–19 year olds say they have no faith. In those over 20 it is 20%, and that goes down to 8% in the 65+ age group. Overall, 21% of the 2,030 people questioned say they have no faith. Of those who do not follow a religion, around one third say they used to be Christian (32%), while three in five have never followed a religion in the past (58%).

[...]

Muslims are much more likely to see religion as "relevant to their life" than Christians (95% vs. 54%), with fewer than half of the people polled saying this overall (43%). The 16–19 year olds are most likely to describe religion as "not relevant" (72% vs. 54% of those aged 20+). Nearly a quarter of those polled say that religion is relevant at all times in their lives (23%); this increases to a third among those aged 65+ (33%) , but falls to 14% among 16–19 year olds . Around a quarter of all people asked say that religion is never relevant (23%)."

National Secular Society, 14. September 2007

As long as parents mislead their children, religious belief will lead to atrocities

"WHAT would turn eight intelligent, respectable doctors and other medical professionals into terrorists bent on a killing spree?

Faith.

For intelligent young people brought up in religious households and grappling with the concept of faith, fundamentalism can be one of only two options: it is either all or nothing. When it comes to faith, there is no logic to holding a moderate viewpoint. You either believe fully that some supernatural being created everything around us and eavesdrops on all six billion-plus of us, monitoring every word and deed, every minute of every day, now and forever, or you don’t."

Irish Examiner, 11 July 2007

[Stats] LifeWay Research Examines Teenagers' Views on Eternity

More than 1,000 [American] teenagers were surveyed in January and February of 2007 by mail questionnaire. These results are compared to an identical survey conducted in 2005. Each sample consisted of 12-19 year-olds.

Though the large majority of teenagers believe heaven exists (69 percent), there has been a 6 percent drop since 2005 (75 percent) in the percentage of teens who are sure in their belief of heaven. Only 5 percent of teenagers strongly agree that they do not believe heaven exists.

African American teenagers are more likely to believe in heaven than the average teen (81 percent vs. 70 percent). Girls (73 percent) are also more likely to strongly agree heaven exists when compared to guys (66 percent).
Four percent of teenagers strongly agree with the statement, “I don’t care if I go to heaven.”

When asked about personal religious activity within the last 30 days, 39 percent of respondents said they prayed regularly and 14 percent said they read the Bible regularly during that time.
Compared to the 2005 results, there are several significant statistical declines. Fewer teens are attending Sunday school (20 percent vs. 24 percent) and small-group Bible studies (14 percent vs. 18 percent).

As for outreach activity, fewer teenagers are discussing their beliefs with friends and inviting them to church activities. Twenty-four percent said they had told a friend about their religious beliefs in the last 30 days (compared to 30 percent in 2005). Fifteen percent had invited someone to a church activity in the last 30 days (compared to 19 percent in 2005).
Female teens are more active religiously than their male counterparts. More females pray regularly (48 percent vs. 31 percent) and read the Bible regularly (17 percent vs. 11 percent) than male teenagers.

The level of teen participation is also higher for females than males for church youth group social activities (26 percent vs. 20 percent), small group Bible studies (18 percent vs. 11 percent), and leadership roles in their church youth group (10 percent vs. 6 percent).

Lifeway.com, May 2007

There are a lot more numbers in the original article. Notice the decline, and that females seems to be more religious than males, and that African Americans seems to be more religious than the average.

See also: Knockin' on Heaven's Door: Teens confused about heaven and how to get there

"A warning signal to the church?
These observations should send out a warning signal to the church: INFLUENCE IS BEING LOST WITH THE FUTURE OF THE CHURCH."

Thanks!