The admision last week that 19 Kids and Counting's Josh Duggar molested girls as a teenager while being part of a family that has strict chastity rules has raised the family's profile, particularly in the UK and among those who don't follow their reality TV show.

Some are using it as an opportunity to criticise the Duggar family's views on Christian purity. Perhaps a better discussion is how Christians approach sexuality and purity more generally. 

"To me what this story shows is the model that they put out is just as flawed as the rest of the world," Craig Gross, founder of XXXChurch, told Christian Today. "I mean is that really attainable? Is saving your first kiss for marriage, and courting, and all the values that they put out there, I think what we've seen with their own family is that there are holes in that system as well."

It's fair to say that over the last couple of decades Christians and churches have got better at talking about sex. Anyone who goes on a marriage preparation course (or marriage course) will have to have that awkward chat, and there's also much more openness to talking about 'silent' issues such as pornography.

But that doesn't mean that we've got it right yet. Culture is constantly evolving, which means we have to adapt our response too. And it doesn't just apply to how we bring up children and educate them (or not) about sex, but also whether we allow ourselves to watch what everyone else is watching, and do what everyone else is doing.

Do we run and hide, or can we find a way to engage with culture in an informed but critical way?

Purity culture... avoid sex at all costs

There are numerous verses in the Bible about sexual immorality and calling for purity of body, mind and heart, often in pretty strong terms. In Ephesians 5 Paul writes: "among you there is not to be even a hint of sexual immorality, or of any kind of impurity". So when faced with our sexualised society, one obvious response is to say that Christians should have nothing to do with any of it.

This view doesn't necessarily mean that the subject of relationships doesn't come up. Quite the opposite. For those who follow this view, it becomes an important distinguishing feature of their lives in comparison with those around them, and the sexual boundaries of romantic relationships are probably talked about more by them than by anyone else. In the Duggar family, for example, the children draw up contracts specifying how much physical contact is permitted during courtship. It's a pretty short list, since even hand-holding is forbidden before they are engaged.

This attitude often goes hand in hand with purity culture: making purity vows marked by purity rings, or purity balls, where daughters promise their fathers that they will save sex for marriage. It's more prominent in the US, but there are less established examples in Britain too, where national prudishness probably also makes us inclined to the 'ignore it, don't talk about it' approach. Another example is the idea that Christian women should dress modestly because they are responsible for leading men astray if they don't (the highly publicised story of the blogger who vowed to give up wearing leggings is just one instance).

In many ways it's a lifestyle to admire. It's about being set apart, keeping yourself pure and holy, and it's espoused by people who want to live out what they believe in the best way they know how.

But this tradition has been widely critiqued, with many writing about the negative effect that this form of abstinence had on future relationships. Gross works with almost 100 Christian couples every week who are struggling with their sex lives, and for many of them it's partly a response to their conservative beliefs in their youth. "A lot of them have brought so much shame and guilt into the bedroom because of their religious upbringing, that sex is still a bad thing."

He says that this response is often rooted in fear: "As Christians we are fearful of anything that seems to be a threat, a challenge or makes us a bit uncomfortable." When it comes to sex, he says: "We just shy away from it, we don't talk about it. We avoid it."

In a conservative environment there is often a clear difference in the way the subject is broached with boys and with girls. Gender justice specialist Natalie Collins says: "It usually puts a lot of responsibility on girls. It uses a lot of the neurosexism about boys not being able to control their sexual desire... and it often assumes that girls don't have a sexual desire at all."

A further problem, aside from the damage that may be done to some individuals, is that sex can become the cardinal sin that is given more attention, than, say, working on developing integrity and character in a context where there is room for grace. This doesn't mean that saying 'no sex before marriage' is wrong, but it might also be possible to interact with culture in a more informed way than proposing what Collins describes as "abstinence without education".

Embrace culture... it's unavoidale

The trouble with the avoidance approach is it's virtually impossible to cut ourselves off from culture altogether. If you walk along the street you'll see a billboard with a scantily clad model; perfume adverts rarely have anything to do with perfume; sexual references and innuendos abound in film, music, TV, videogames and social media memes. If you want to avoid references to sex, you might have to go lock yourself in a dark room without broadband. Like it or not our culture is more permissive, and we will inevitably take it in by osmosis. So an alternative response says that since we can't avoid it, we might as well accept it.

Those who take a more 'anything goes' approach argue that we shouldn't be in silos, cut off from culture, if we are to have meaningful relationships with people and understand their needs and experiences. They might also point to the damage that is done when people do try to cut themselves off. And, for some, there's a sense that our sexualised culture doesn't seem to be doing too much harm – or at least nothing more than people have always struggled with; sexual abuse is not a new problem. The ongoing revelation about widespread historic sexual abuse by influential figures far predates the days of Miley Cyrus flailing around on a demolition ball.

Biblical justification for this view includes the idea that we should be 'in the world but not of it', based on Jesus' prayer for his disciples in John 17: "My prayer is not that you take them out of the world but that you protect them from the evil one." One application of that verse is that we should know what's on TV, share a common language, but that it's God's responsibility to protect us. Others might point to Paul's understanding of Greek culture in Acts 17 when he points to the 'unknown God'. Even though he was criticised by those around him, Paul's knowledge of the surrounding culture enabled him to speak to them about Jesus.

But in reply some would quote 1 Corinthians 10:23: "'I have the right to do anything,' you say – but not everything is beneficial. 'I have the right to do anything' – but not everything is constructive." Collins says: "We shouldn't be restricting ourselves because somebody somewhere says that's a bad thing, but we should maybe be thinking 'how is that affecting me personally?'."

In any response we have to make judgements about what we think is ok and what is not – we have to choose to draw the line somewhere. For example if you say that sex before marriage is ok, what about multiple sexual partners? While Gross says that some couples he meets are struggling with their conservative upbringing, there are also others who have had so many sexual partners that they no longer know how to connect with one person.

And contrary to the idea that a highly sexualised culture does no harm, Collins says that there are very few expressions of sexuality across culture that aren't degrading to women. "That's the bigger issue with the sexualisation of culture – the way that it degrades and objectifies women." While Christians might say that sexualisation is wrong, she says they would rarely point out which bits are wrong, such as distinguishing between sexual abuse and positive representations of sex.

Accept culture... but question it

We can't ignore what the Bible says about sexual immorality. We also can't ignore the people and the views espoused around us. But just because we are surrounded by a certain culture, doesn't mean we have to consume it uncritically. One way to bridge these positions is to ask more questions about the effect the things we see and experience have on us and on our family, and whether or not we agree with the image of humans and human relationships that is being presented to us.

For Gross, that means pre-empting conversations with his own children. He argues that parents should try to be the first to talk to their children about sex, not the last. People often tell him that if you talk about sex with your children you will plant the thought in their minds, but he says: "A kid knowing the good about sex or what it's meant for in a positive way, doesn't mean that your eight-year-old, just because you told them about it, is going to want to have sex."

Instead he says it makes them more likely to talk to you about sex when you're open about it, it's no longer a "bad word" or an "off limits conversation". "When I see examples of what takes place in the world; whether that's the Duggars, or a billboard taking about free STD checks I'm able to talk through those situations with my kids, rather than covering their eyes and keep driving." And of course the world we live in means it's no longer possible to hide everything from view even if we wanted to.

Similarly, Collins advocates talking to children about porn before the age of 10, because otherwise it's often too late to help them think through what they are likely to see. "We need to be equipping children to know that there's going to be stuff that they see that's not very nice, or that's not very kind, or that's kind of 'creepy and naked'... There's this idea that we're destroying innocence if we tell them about pornography... The reality is innocence isn't destroyed through education, but through not having the tools to be able to shape what you've seen."

She has brought her children up to question every sexualised image they see and think what it says about them as human beings. This isn't just good practice for children, it's something we would all do well to apply. Collins suggests thinking about who is the 'subject' and 'object' in images around us and the power relationship depicted. About 99 per cent of the time, she says it is women who are portrayed as 'passive'.

As with encouraging a questioning mind set, so too adults should commit to having awkward conversations with each other – not just between parent and child. Gross admits he's often surprised by the number of people who haven't talked to their spouse about their sexual past or their sexual expectations. And those who are single need to be prepared to be accountable and to challenge themselves about how they respond to culture. It's not just a case of saying either everything or nothing is permitted. Each family, each individual has a responsibility to decide for themselves what is helpful, and to continue asking questions.