Today, sex is both a commodity to be accessed at the swipe of an iPhone, or exchanged in a nude-selfie; but also the source of personal identity. Living with integrity, in the modern view, means that one has to be true to oneself, believing and engaging in any kind of sexual expression — as long it causes no harm. And when it comes to identity: "you are who you think you are", not what your body or society dictates.

Anyone who critiques this radical individualistic lifestyle is treated as bigoted, puritanical and evil.

Christians believe that foundational to a life of sexual integrity is the development of a Bible-based sense of identity, including sexual identity. Building on this is an understanding of God's plan for a redeemed model of sex and sexuality, and the ability to critique unhealthy world views on sex. Christians are called to model true integrity in a fallen world (1 Pet. 2:12).

Our society surrounds us with challenges and role models of perceived perfection. "Be like me!" Desire what I have, work at being like me. It will make you happy and fulfilled. Or else, ignore society and even your own anatomy and mould yourself to be whoever you wish: gay-lesbian-bisexual transgender. Sadly, neither the performance and possession lifestyle nor individual self-determination makes us truly content. Rather it results in poor self-esteem, depression, self-harm and even suicide.

The Bible offers us an identity that is not based on our performance, possession or sexuality. Not even on our goodness — however virtuous that may be. We are created by God in His image — embodied and gendered male and female (Gen. 1, 2), known by Him (Ps. 139) for the sinful and imperfect people we are (Rom. 3:10-18). God knows our thoughts and desires. He understands our longing to belong.

And in Jesus' death and resurrection we see God's solution. Our self-worth and our identity as redeemed people are the free gift of grace. They make us children of God and adopted brothers and sisters with Jesus (Eph. 1:3-10, Rom. 8:15).

How do we live out this redeemed Christ-based identity in our sexualised world?

Sexual satisfaction is assumed a prerequisite for healthy life. Individuals have a right to define what sexual satisfaction means to them: in values, behaviour and self-hood. No-one, least of all "God" or "the Church", has the right to decide how a person should desire, or act sexually.

Sexual desire, the testosterone-driven "want" for sex, is perceived a natural need that must be met, not controlled, whatever this desire may be: pornography, paraphilia or same-sex attraction.

What about falling in love, that dopamine-fuelled thrill of limerence? Love is equivalent to lust. To love is to want sex. What is important is my enjoyment. Sexual gratification is detached from committed monogamous heterosexual relationships. And so we have casual sex, hook-ups, premarital sex, cohabitation and de-facto relationships. Are we happy? Sadly — no. Early sexual activity leads to confusion, risky behaviour and difficulty in later relationships. Cohabitation before marriage is unsuccessful with a higher divorce rate and more dissatisfaction than in couples who don't.

What of marriage? Marriage as a one-man, one-woman committed life-long relationship seems outdated. Infidelity, is good for a relationship, and monogamy outdated. Or, we can redefine it anyway we wish — in same-sex or polygamous relationships.

Where does this leave Christians? How can we live by the biblical view of sex, love and marriage in a sexualised world? And what is God's pattern anyway?

To do this we need to turn our focus away from a worldview and explore the biblical view of sex. We then see sex as a wonderful and precious gift to be treated with care and honour when single and enjoyed in marriage and, like all our lives, used to bring God glory.

To do this, first, we need an evangelical, theological understanding of sex: a perspective on what it means to be sexual and behave sexually. Second, we need to be empowered to take on the worldview and live a countercultural lifestyle that is winsome and attractive to society (1 Pet. 2:12).

In a biblical model, sexual desire is good and powerful. It's meant to operate in harmony with falling in love with a particular person, as we see in the joyous description in Song of Songs (8:6-7). It is powerful, and needs to be held in control till the appointed time. Three times in Song of Songs (2:7; 3:5; 8:4) we read: "Daughters of Jerusalem, I charge you: Do not arouse or awaken love until it so desires."

Today, the science of neuroplasticity and epigenetics informs us that what we feed our brain, especially in the developing teen years will affect what we desire and value in life. Any wonder that the apostle Paul emphasises the importance of what we feed our brains (Phil. 4:8).

Sex is purposeful: God created man and woman with complementary bodies and suitably matched brains. It has the purpose of procreation as well as pleasure as we hear from Adam when he meets Eve (Gen. 1:26-30; 2:20-25).

The ultimate desire of the human soul, body and brain is a relationship with God. The desire for earthly relationships and intimacy is a reflection of this. We best enjoy our sexual desire in the context that God gives us: a one-flesh marriage relationship.

What about love? In God's plan, love is not a narrative of self-expression and self-realisation, not about finding a soul mate who "completes me". Rather, love focuses the energy of sexual desire towards the beloved. "I love you" means "I honour you and care for you". It is an intimacy based on total vulnerability and ultimate trust of body and soul (Gen. 2:24-25).

How is this expressed in a couple's life? Couples would seek to honour rather than possess the lover's body, and build non-sexual intimacy. Marrieds would demonstrate "one-flesh" love in action accommodating to and, if needed, sacrificing for the other.

Christ laid down His life for the church to make her holy, an act which the apostle Paul analogises to the love of a husband and wife (Eph. 5:25-33).

Marriage in God's plan is a covenant, not some ideal we aspire to. Making love in marriage is a sacramental act one in which we celebrate the covenant (Prov. 2:17; Mal. 2:14).

This counter-cultural sexuality may lead to harassment and even abuse (1 Pet. 4:4), but sexual desire, falling in love and marriage lived according to God's plan is good for us individually, as a couple, our church and for society as a whole.

We recognise that we can't do it on our own, but we know that it is God who works in us to will and to act in order to fulfil his good purpose (Phil. 2:12b-13).

The word of God written in the Bible and incarnate in his Son Jesus gives us hope for our life — including our sex life — whatever age we may be, or whatever stage of life we may be at, whether we are sexually inexperienced, sexually active or even sinned against. It is a hope we can rest on while we live our lives here on earth. But finally, it is the wonderful hope of a new creation of a perfect untainted relationship with our creator God and his son Jesus to which we aspire.