Opinion by Hemant Mehta, Special to CNN

(CNN) - Articles and books about why millennials are leaving Christianity often focus on what churches are doing "wrong."

They're anti-gay, anti-women, anti-science, anti-sex-education and anti-doubt, to name a few of the most common criticisms.

I don't disagree with those critiques, but there's another side to the story.

While Christians have played sloppy defense, secular Americans have been showing off some impressive offense, giving young Christians plenty of reasons to lose faith in organized religion.

For instance, atheists dominate the Internet, rallying to thriving websites and online communities in lieu of physical meeting spaces.

Even a writer for the evangelical magazine Relevant admitted that “While Christianity enjoys a robust online presence, the edge still seems to belong to its unbelievers.”

Atheists outnumber Christians on popular discussion forums like Reddit, where subscribers to the atheism section number more than 2 million. The Christianity section is not even 5% of that.

The Internet-based Foundation Beyond Belief, which encourages atheists to donate to charitable organizations, just celebrated raising $1 million for worthwhile causes. (Disclosure: I serve on its board of directors.)

Moreover, blogs and websites espousing non-religious viewpoints and criticizing Christianity draw tons of Internet traffic these days. For every Christian apologist's argument, it seems, there's an equal and opposite rebuttal to be found online. I call that "Hitchens' Third Law.”

READ MORE: Why millennials are leaving the church

Christians can no longer hide in a bubble, sheltered from opposing perspectives, and church leaders can't protect young people from finding information that contradicts traditional beliefs.

If there's an open comment thread to be found on a Christian's YouTube video or opinion piece online, there's inevitably going to be pushback from atheists.

There has also been a push by atheists to get non-religious individuals to "come out of the closet" and let people know that they don't believe in God.

Among other things, this proves that anti-atheist stereotypes aren't accurate and, just as important, that atheists aren’t alone in their communities.

There's the Richard Dawkins Foundation's Out Campaign, with its Scarlet A badges.

There are atheist-encouraging billboards in 33 states financed by groups like the United Coalition of Reason.

There's even going to be an 1-800 hot line for people "recovering" from religion.

READ MORE: Atheists to start 1-800 hot line for doubters

And last year, an estimated 20,000 atheists turned out for the Reason Rally in Washington, a tenfold increase from the previous atheist rally in 2002.

But more than anything else, atheism's best advertisements may be the words of Christian leaders themselves.

When Pastor Mark Driscoll belittles women, Rick Warren argues against same-sex rights or Rob Bell equivocates on the concept of hell, we amplify those messages for them - and it helps us make our point.

(It goes without saying that the pairing of Pat Robertson and YouTube has been great for atheists.)

Pastors are no longer the final authority on the truth, and millennials know it.

Even if they hold Jesus' message in high esteem, the Bible as it has traditionally been preached by many evangelical pastors is becoming less and less attractive to them.

A 2012 study by the Public Religion Research Institute (PDF) showed that many Christians aged 18-24 felt that Christianity was hypocritical (49%), judgmental (54%) and anti-gay (58%).

In addition, Christianity Today reported last year that fewer than half of born-again Christians under 35 opposed same-sex marriage.

When millennials' pastors and hearts are going in different directions, church leaders should be worried.

Can churches win back the youth?

Barring a complete shift in beliefs, that may not be possible. Some of the proposed solutions seem ludicrous to millennial atheists like myself.

For instance, there's been talk of finding a better way to reconcile science and religion. Whenever that battle takes place, religion loses.

There are some questions we may never know the answer to, but for the ones we can eventually answer, the scientific explanation will devour the religious one. Mixing science and religion requires a distortion of one or the other.

READ MORE: Behold, the six tribes of atheism

What about focusing on the message and life of Jesus?

While this sounds good philosophically, the myth surrounding Jesus is part of the problem with Christianity.

To believe in Jesus means believing that he was born of a virgin, rose from the dead and performed a number of miracles.

There's no proof of any of that ever happened, and atheists place those stories in the same box as "young Earth creationism" and Noah's Great Flood.

To be sure, if Christians followed the positive ideas Jesus had, we'd all be better off, but it's very hard to separate the myth from the reality.

In short, there are many reasons the percentage of millennials who say they've never doubted God's existence is at a record low, and nearly a quarter of adults under 30 no longer affiliate with a faith.

The church has pushed young people away, yes, but there are also forces actively pulling them in the other direction.

It appears that atheists and Christians are finally working together on the same task: getting millennials to leave the church.

Hemant Mehta blogs at The Friendly Atheist. The views expressed in this column belong to Mehta.

Photos: Famous atheists and their beliefs