I asked the teenagers: 'On a scale of one to ten, how likely would you say it is that boys and girls your age are watching porn online?'

The reply was a chorus of tens, nines and one eight.

When I asked the children if there were parental controls on the internet at home, they all said no, their parents trusted them. They all admitted their parents had no idea what they were watching, and would be shocked if they did know.

What I saw at the school was awful, but sadly not unusual.

The findings were backed up in a survey of 80 boys and girls aged 12-16, commissioned for the TV show.

It proves the vast majority of UK teens have seen sexual imagery online, or pornographic films.

According to the survey, the boys appear largely happy about watching porn - and were twice as likely as girls to do so - but the girls are significantly more confused, angry and frightened by online sexual imagery. The more they see, the stronger they feel.

But what impact is this steady diet of online depravity having on the attitudes of boys and girls towards real life relationships, and on their self-esteem?

Could it even have a wider impact on their lives, blighting their ability to function in the world, get good qualifications and jobs?

You might be surprised. After all, from 2003-2010 I edited lad's magazine Loaded.

With its frequent nudity and lewd photo spreads, I'd long been accused of being a soft pornographer, and after leaving Loaded I agonised that my magazine may have switched a generation onto more explicit online porn.

In the documentary I set out on a journey to answer the question: is porn harmless, or is it damaging lives?

My interest was deeply personal, too, as my own beautiful little boy, Sonny, is now four. Even though he has only just started primary school, the Children's Commissioner estimates boys as young as ten are now being exposed to online porn.

I wanted to know what I could do to protect my own son from a seemingly inevitable exposure to hardcore material in just a few years' time.

I used to be sceptical that porn was as damaging a force as the headlines and David Cameron - who recently said it was 'corroding childhood' - suggest. In the past I'd even defended pornography in university debates, on TV and on radio. I claimed it was our freedom of choice to watch it and said it could actually help add to adult relationships.

But what I saw during the making of the film changed my opinion of pornography forever.

I'm one of those people who hates confrontation and would do just about anything to avoid conflict. So it may come as a surprise that I'm also an apologist for the Christian faith, an enterprise that involves disagreements of all kinds.

1 Peter 3:14 tell us, "Always be prepared to give an answer to everyone who asks you to give the reason for the hope that you have." An atheist quoted that verse to me right before asking why I believed in God. I quickly realized for the first time that my Christian faith was largely grounded in experience. My reasons for believing were valid, but not convincing for someone looking for arguments based in logic and reason.

Even after I did my homework—learning the arguments for the existence of God and the reliability of the Bible—I quickly discovered I also had to know the right way to articulate them, particularly in the face of the insults and mockery some atheists like to substitute for intelligent and reasonable dialogue. I didn't just study the "what" of apologetics; I studied the "how," turning to guides such as Greg Koukl's Tactics.

Judging by the dearth of women in apologetics, I'm not the only one who doesn't like disagreements and strives for peace in all things. Sheryl Sandburg's Lean In brought up once again women's hesitancy to be assertive, even in situations when we have a cause to fight for. Women are actually more underrepresented in philosophy—a field overtaken by aggressive debates, according to Freakonomics– than in math and science.

This topic will cause some discomfort for many of you. The very thought of the presence of power groups seems contrary to the spirit and grace of the gospel. But power groups are very real in churches.

Perhaps our comfort level can increase a bit by calling the groups "influencers" rather than power groups. Choose your label. The fact of the matter is that most churches have a clearly known group that carries the most influence in the church. And it is not unusual for that group to have a clearly known leader.

It is common to assume that power groups are inherently bad. That is not necessarily the case. Some of them can be a part of the formal structure of the church; church polity requires them. But even some informal groups can be healthy for the church. Don't assume a power group per se is negative. Here are eight types of groups. While a church may have more than one kind of group, only one of the groups will be the dominant power in the church.