Like many computer pros whose lives revolve around the Internet, Marc Yoder eventually created a weblog in which to share his views on life, technology, faith and other cultural issues that happened to cross his path. His "Marc5Solas" site -- the musings of a self-proclaimed "nobody from nowhere" -- drew a quiet hundred readers a week.

Then the 42-year-old Yoder wrote his "Top 10 Reasons our Kids Leave Church" post, based on dozens of face-to-face conversations with college students and 20-something agnostics and atheists in San Antonio. He offered them coffee, the occasional lunch and a chance to vent. They did just that.

"We all know them, the kids who were raised in church. They were stars of the youth group. They maybe even sang in the praise band or led worship," noted Yoder.

Then they vanish. About 70 percent slip away somewhere between high school, college and the office, according to researchers. How many return?

"Half. Let that sink in," noted Yoder. "There's no easy way to say this: The American Evangelical church has lost, is losing and will almost certainly continue to lose OUR YOUTH."

Before he knew it, 500,000-plus people had visited the website and his manifesto went viral on Twitter and other social-media platforms. Then the agonized digital epistles began arriving. A few religious leaders started looking for the man behind the brash post.

"There was lots of church bashing, but I expected that," said Yoder, reached by telephone. What hit him hard were the "worried voices" of "people concerned that something fundamental had gone wrong in modern churches and they couldn't put their finger on what that something was," he said.

What Yoder had done was tap into one of 2012's hottest cultural trends, which was the rise of the "religiously unaffiliated" -- the so-called "nones." The key numbers emerged from research backed by the Pew Forum on Religious & Public Life and the PBS program Religion & Ethics NewsWeekly.

The study's findings have loomed over a variety of news events in recent months, from debates about gay marriage to the challenges facing a new pope. The key facts: One-fifth of the U.S. public -- and a third of adults under 30 -- are now religiously unaffiliated. The ranks of the unaffiliated have risen, in only five years, from about 15 percent of American adults to nearly 20 percent. This trend appears to be accelerating.

What is happening with the dropouts? Among Yoder's blunt observations:

* Churches offering the atmosphere of Starbucks/Dave & Buster's "knockoffs" are no longer cool for the young. "Our kids meet the real world and our 'look, we're cool like you' posing is mocked. ... The middle-aged pastor trying to look like his 20-something audience isn't relevant. Dress him up in skinny jeans and hand him a latte, it doesn't matter. ... The minute you aim to be 'authentic,' you're no longer authentic."

* Many young people have never been to a real church, since they were raised in multi-media nurseries and then taken into hip church services built around jumbo video screens and rock bands. "They've never sat on a pew between a set of new parents with a fussy baby and a senior citizen on an oxygen tank," he argued. In short, many have never seen faith applied to the full timeline of real life.

* Rather than teaching tough truths about tough issues, many religious leaders now sell a faith rooted in emotions and pragmatism. "Rather than an external, objective, historical faith, we've given our youth an internal, subjective faith. The evangelical church isn't catechizing or teaching our kids the fundamentals, ... we're simply encouraging them to 'be nice' and 'love Jesus'," he said.

* Young people are also supposed to be winners all the time and there is little room for "depression, or struggle, or doubt" in many big churches, argued Yoder. The bottom like: "Turn that frown upside down or move along."

It's hard to talk about sin, repentance, grace and forgiveness in that kind of happy-talk environment. Far too many of what Yoder called the "big box" churches are not the kinds of places in which young believers learn to wrestle with the timeless tragedies and modern temptations of life.

"The church," he said, "is simply a place to learn life-application principles to achieve a better life. ... You don't need a crucified Jesus for that."