The NOW 94 compilation CD was on continual loop in our family minibus this Summer. One of the songs that would always get the passengers singing along was DNCE's breakout debut single Cake by the Ocean. It's a very funky tune with a brilliant hook that earworms its way into your brain. The eight-hour drive to the beach we visit in France each summer meant that we had plenty of opportunity to get into the groove with this song. Although one of the older teenagers was not quite as enthusiastic. When I asked why I discovered Cake by the Ocean is a euphemism for Sex on the Beach and not the cocktail variety.

Sex and pop have long been intertwined. It's why historically many conservative Christian commentators were nervous about its corrosive effect, preferring total abstinence. From the birth of rock and roll (also a euphemism) to the licentious soundscape of the sixties, sexuality and music are hard to separate. Listen closely to the top-selling songs of this year and again sex is centre stage.

The back story to Cake by the Ocean can be understood as a microcosm of the interaction between Christianity and sexuality and so it is worth taking a closer look.

Joe Jonas, lead singer of DNCE, and his brothers Kevin and Nick were brought up in a conservative Christian home. Their father, also called Kevin Jonas, was an Assemblies of God pastor and a musician and worship leader and the boys were home-schooled by their mother. Nick Jonas' talents as a singer and actor were spotted early and by the age of six he was performing on Broadway. Pretty soon Nick and his brothers were signed to a record label, performing on Disney Channel and well established as a boy band. The teenage Jonas Brothers band became a huge commercial success selling millions of records and starring in movies such as Camp Rock and Camp Rock 2. As young, attractive Christian young men they were quickly seized upon to be the poster boys for the purity ring movement. These rings were a public pledge. As Kevin Jonas put it: "my ring represents a promise to myself and to God that I'll stay pure until marriage."

You don't have to listen very closely to Cake by the Ocean to know that Joe Jonas has moved on from his Disney past. He drops the F-bomb numerous times and it's hard not to hear sexual innuendo in most of the song's lyrics. In interviews all of the Jonas Brothers seem to have distanced themselves from their purity ring past. Joe Jonas explained to New York Magazine:

"Back then, we explained that we had made these promises to ourselves when we were younger...People were coming up to us, saying, 'Thank you so much, I'm waiting because you guys are, too!' And we just thought, No! That's not what we're about."

Sexual intimacy is something the Bible celebrates. The Bible story starts with naked people in an idyllic garden. The first recorded words of a human being are a love poem. The Bible includes a whole book of erotic verse full of sexual innuendo about watermelons and gardens. The New Testament kick-started a sexual revolution when it challenged the prevailing cultural norms and argued that both men and women were to enjoy sex and that prayer was no substitute for intercourse.

Purity rings, on the other hand, are a modern day invention. I have some reservations about them. Imagine a recent smoker tattooing their forearm with the words "I don't do cigarettes". Firstly every time they see the tattoo they are going to be reminded of cigarettes, which potentially will increase their craving. Secondly instead of using their body to celebrate the things they can do, their primary identity marker to the outside world is about what they don't do. The Bible is clear about the best and safest context of sexual activity, however Jesus, the purest person that has ever lived, was very keen to associate with people who had failed their cultures purity standards and were socially excluded. His main message was one of welcome, and of forgiveness and reconciliation with God. In my mind, it is the Pharisees, the Jewish ruling elites, who would have been more likely to have started a purity ring movement than Jesus.

I am not surprised that the Jonas brothers have moved away from their strict upbringing, but it is a shame they seem to have thrown the baby out with the bathwater. It is neither in public principles of abstinence nor in public promiscuity (red velvet, vanilla and chocolate as Joe Jonas puts it) that sexuality is best enjoyed. What I would love Joe to know is that the essence of the gospel is not confined to what you have, or have not done in the past. It is that because of the purity of Jesus, all can find welcome, grace and forgiveness and live life to the full.

Dr Krish Kandiah is the founding director of Home for Good and a contributing editor to Christian Today.