Covenant and Sex: God’s Answer to Lust – Matt 5:27-30

NOTE: problem with second voice on audio track for first 3 minutes only


Ashley Madison website: “life is short, have an affair”

[Acknowledge Tim Keller[1]]

Read Matt 5:27-30

God’s intention for sex

Last week Jesus was addressing the 6th commandment, this week it is the 7th commandment.  And again, we see that the Pharisees had relaxed the commandment to the purely physical act of adultery.  Our society may question whether there is anything wrong with adultery, but Jesus goes the other way.  He sharpens and intensifies the 7th commandment.  Why?

Sex and marriage

Adultery is about the misuse of sex.  To properly understand what Jesus is going to say, we need to understand God’s original intention for sex:  exclusively within marriage; only within the context of the covenant of marriage.

There is no other relationship in which human beings can share on this earth like marriage.  It is the highest and best of relationship – and so God gives uses a special term to define it and a special act to consummate it.  The term is covenant.  The act is sex


Marriage as a covenant is infinitely more than binding than the legal relationship into which you enter which the government recognises as a legal relationship.  It is also infinitely more loving than any other emotional relationship in which you may find yourself.

The best way to understand that is to contrast covenant relationship and consumer relationship.  We have been so deeply programmed by our culture: there is a consumer and a retailer/shop/company and their job is to keep the customer happy (meet my needs, innovative product, price point, good value proposition): “If you don’t I will go somewhere else, get a better deal”.  The consumer relationship is: you adjust to me or I will leave; me and my happiness is the priority, the relationship is secondary at best.

Covenant relationship is the exact opposite: I adjust to you because the relationship is a priority.  I know that sounds simplistic – but take a moment to consider how beautiful and sustaining it is:

  • Only way to give true love: true love is not about convenience, it is costly. You learn to truly love when you have to forgive, serve, and be patient.  Love is not a feeling it is an act, it is a decision.  And as you do that deeper feelings of love grow and the relationship becomes deeper and more satisfying.
  • Only way to receive true love: it is the most freeing thing to be loved unconditionally. You be who you really are without fear of rejection, ridicule or retribution.  You can stop putting up a façade, expose your weaknesses and insecurities and find acceptance and a partner who will journey with you towards healing.

In a covenant, you can stop selling yourself; stop living in fear of the other party pulling out or rejecting you; stop living on performance.  You can freely priorities the other person and the relationship.  Now what does that have to do with sex and adultery?


Outside of marriage sex becomes a consumer good – something it was never intended be (and we will see it misfires).  Within marriage sex is the consummation of the covenant relationship.  Sex serves as a covenant renewal ceremony.  It serves to renew and rekindle the commitment you made as a married couple.  It serves marriage like the sacraments of baptism and the Lord’s Supper serve the church: it is an external and visible sign of an internal and unseen reality.  When you have sex completely physically naked and exposed and vulnerable – and you are saying to your partner that I am also emotionally and spiritually exposed and naked with you.  Sex is an act of self-giving – in the most intimate way you give yourself entire self to another person.  It says: I am your completely – oneness.

Sex outside of marriage: you are asking someone to do with their body what they are not doing with the rest of their lives – oneness in sex, but not economic, residential, legal, personal, psychological.   It is consumeristic: do you satisfy me and do you continue to satisfy me? Can I do better than this?  Should I look for an upgrade.  In an American study of couples who were living together but not married, one lady’s comment represented many people’s feelings: “I felt like I was on this multi-year, never-ending audition to be his wife.”  What she is saying that sex outside marriage is not about trust and giving and renewing – it is about: “is she good enough for me or should I keep looking for a better deal?”  It is satisfying for the moment, but I think I could do better.”  And therefore, sex outside marriage in no way prepares you for sex in marriage.  Cohabitation is learning to live together as consumers instead of married couple living as covenant partners.

Our feelings of lust

You can’t understand what Jesus is saying about adultery and how he presses into the heart unless you understand the Bible’s teaching on the right place of sex.

The word here for ‘lust’ can be used of both good and bad desire – it is determined by the context. It simply means to “set your heart on”.  The look here is not a passing glance it is the heart that is set on something that does not belong to it, latches onto that look, the looking becomes purposeful, there is desire, starts to fantasise and covet.   John MacA suggests this translation: “Emphatically I say to you that whoever continues looking on a woman for the purpose of lusting gives evidence of already committing adultery in his heart.”[2]

Put that together with God’s covenantal purpose for sex and we can identify some ways this happens:

  • Voyeuristic looking – a passing glance that becomes a stare, flipping through channels, entertaining fantasy in your mind, flirting…
  • Emotional attachments – the heart can long for the romantic appeal and excitement that the interest of another person brings. You end up communicating in a secretive way, comparing your spouse, romantic fantasies, making ways to spend time with the person, dressing to impress that person.[3]
  • Pornography and the masturbation that goes along with it. If sex is meant to be covenant renewal between two people this is the epitome of a consumer good.  It is not giving, sharing renewing – it is selfish, where you want it, when you want it, focussed on myself.

Just to quickly answer those who say – well pornography and masturbation don’t really hurt anyone and it won’t affect my relationships.  Mark Regnerus and Jeremy Uecker have written an empirically (observation) based booked called “Premarital sex in America” – but not from a Chirstian perspective.  They say that Pornography affects everyone (in the whole of society):

  • It causes unrealistic and crushing expectations about how a partner must perform in bed;
  • It diminishes the tolerance for the difficulties that a real relationship brings and that is shrinking the pool of men who will marry;
  • “all woman we argue are increasingly being forced to accommodate sexual behaviour and their appearances so the images in the style of pornography.”[4] So magazines, movie, fashion, boyfriends, etc.

Our ruthless response

Jesus sets out a ruthless response for Christians.  Jesus is not calling you to do physical damage to yourself.  If you plucked out your right eye or your right hand can your heart still lust?  Of course!

The reason he says right eye and right hand is that the Jew considered right to the best and strongest.  So Jesus is saying: whatever you need to eliminate from your life – no matter how strong or precious or important – protect your heart from adulterous desires.  Jesus is saying: “What is that feeds your lust?  Cut it off”.  Today men measure themselves by the conquering ladies, Jesus measures you by whether you have conquered lust

God’s gift of love

In verse 29-30 Jesus says that wrong use of sex in lust that leads to heart adultery and physical adultery points us in the direction of hell.  We won’t get too deep into the question of hell this late in a sermon, but I think most people would agree that hell is separation: from God an all his goodness and provision.  Jesus is warning that wrong use of sex and sexuality drives you from God’s goodness and provision now and ultimately.

On the other hand, the right use of sex and sexuality points towards heaven – ultimate fullness and enjoyment of God himself.  Sex in a consumeristic way points to hell; sex in a covenant points to heaven.  How so?

The whole story of the Bible is interwoven with marriage.  The Bible starts with a marriage (A and E), it ends with a marriage (Marriage feast of the Lamb), and all through there is the theme of God the faithful husband and Israel the unfaithful and spiritually adulterous wife.  The passages in Romans 7 and Ephesians 5 indicate that the most rapturous love between husband and wife is a dim foretaste of falling into the arms of our true spouse at the end of time.

What am I saying?  As wonderful and beautiful as my relationship is with Joanne, there are times when I don’t love and accept her unconditionally and the sharp edge of my judgement or rejection pierces her heart and she withdraws from total vulnerability and feels insecure.

When it comes to perfection, I am a failure as a husband.  But there is a marriage, there is a covenant into which I can enter where I will find a perfectly unconditional, unfailing love.  The extent of that love is demonstrated by Jesus as he forgives my spiritual adultery, my lust of worldly things, my affair with sin.  He is not a consumer – he serves me, he is patient, he makes relationship possible through his death.

Joanne can never be a perfect spouse and if I place the expectation on her I will crush her and damage our relationship.  I can never be a perfect spouse – but when I am in a covenant marriage with God it transforms my ability to love: having received and been deeply changed by the love of Christ, I am able to love more and more like him.


Some of you need to repent:

  • Heart adultery
  • Physical adultery

If your marriage has grown stale and distant, perhaps you need to revisit and re-enact the covenant.  Sex is the physical re-enactment of the inseparable oneness in all your whole life.  Sex renews and revitalises the marriage covenant.

Although sex outside of marriage and/or cohabitation are against God’s plan for mankind, it is not an unforgivable sin!  If you have messed up there is forgiveness and reconciliation with God.  There is no sin, when we come in repentance, that God does not forgive.

If you have been hurt, you committed adultery, or adultery was committed against you.  Let us pray for you for healing.


Sermon Questions

Please use / augment / discard these questions so that your group has a fruitful discussion

  1. Grant contrasted a covenant view of marriage and a consumer view of marriage.  How does this help us understand that beauty of what marriage can be?
  2. Why is the covenant of marriage the perfect place to learn how to be loved and how to love?
  3. How does sex operate in a consumer relationship?  How does sex operate in a covenant relationship?
  4. Discuss this statement by C. S. Lewis: “The monstrosity of sexual intercourse outside of marriage is that those who indulge in it are trying to isolate one union (sexual) from all other kinds of union, which are meant to go along with it and make up the total union.
  5. Discuss John MacArthur’s translation of Matthew 5:28, “Emphatically I say to you that whoever continues looking on a woman for the purpose of lusting gives evidence of already committing adultery in his heart.”
  6. What are the avenues of lust in our 21st century culture?
  7. What response does Jesus call for?
  8. How does Christ fulfil the longings of our heart to be truly loved?
  9. How does the gospel empower us to love more like Christ?

[1] Tim Keller sermon “Love and lust”



[4] Mark Regnerus, Jeremy Uecker – “Premarital sex in America”.