This transcript has been automatically generated, and therefore may not be 100% accurate.

Right. Thank you. Keep your hand in the one Thessalonians passage. I'm going to also refer to a couple of more verses. Beyond the reading that's just been read to us.

This is a tough passage. And preaching a sermon on this. Sometimes you think you could be like the equivalent of a primary school teacher. Telling everybody off a lot for things they haven't done. So rather than tell you off.

I mean, I had 32 years of that as a secondary school teacher. Rather than tell you off. I want to see if we can find some principles as to how we live here. And now.

One thing is very clear in this area. Every single person makes mistakes in the area here. So, purity. In a world obsessed with sex. Every single one of us.

At some point you may be saintly this evening, but at some point in your journey, either now or later on, you will make mistakes in this area. So we don't start from our essential holiness. If you're going to talk about any belief about sexual behaviour, I think you always have to start with one of the stories and encounters of Jesus. I think you have to start with the woman caught in adultery. That story of the woman brought to him.

And Jesus says two things to her. He says, you know, I forgive you. I forgive you. The past was not what it should have been, but I forgive you. And then he says, go and don't do it again.

So this area is an area where forgiveness is available. And forgiveness should be sought. It may be that there are some things that have happened sexually. That are so difficult. That it will take quite a long process.

And we may have to face up some difficult things about ourselves. But for most of us, most of us, I hope this area of forgiveness can be cleansing. So purity is pretty difficult in a world like we live in today. Think about the development of communication. In the 1970s and eighties.

Sexual images could be available through the cinema. The development of the DVD, the pornographic magazine. Now, as we sit in church, they could be available to you on your phone. There are, more than any other time in history, the opportunity to see things that perhaps are better not seen. So this is going to be a constant struggle.

Okay, let's try and think of some things that can help and support us. So we've heard that there is the ideal of one flesh right at the beginning there. The passage from Genesis. Marriage is a radical thing in today's culture. Committing yourself and being with someone and showing true love and care for them.

Learning not to be selfish, but to develop trust and relationships. That is a very high calling. And that's what many christians are called to do. Some aren't, some are called to a different way.

We need to pray for those of us who are married. We need to pray for the stability of those relationships. We need to pray that we are honest and humble with each other and that we are listening and encouraging each other. God is a God who gives second chances, but he gives many more than those as well. Forgiveness is available in this area and in marriage.

Well, it may be an education in our own selfishness sometimes that we learn just how selfish we begin, but it's an area that we can all learn from.

I want to say that holiness is a body thing, it's not just a spirit thing. So what do I mean by that? So if you look at the passage in one Thessalonians, Paul says this, each of you should learn to control your body in a way that is holy and honourable bodies are potentially holy. Paul uses another expression later on, before actually in the New Testament, he talks about the body being the temple of the Holy Spirit. The idea that there's this bit of us called spirit and a bit called body, well, actually that's okay.

But it's also our bodies are holy to God, can become holy to God. And if your body is a temple, then treat it like a temple.

Holiness is a body thing. God wants us to learn to treat our bodies with respect. Now, this applies to sex, but it also applies to other things that we do with our bodies. What we eat, how far we exercise, how far we care for it, what we put into our body. Holiness can be a body thing.

It's not just a making sure you pray, making sure you go to church thing. What you do with your body reveals what you think about God. And if you take his holiness seriously. And the idea of your body being a temple of the Holy spirit, that's really very, very important.

Now, I did say I wanted to add on one verse to the reading that we had in particular. So if you look at verse six, it says this, in this matter, you should not wrong or take advantage of a brother or sister. So Paul's talked about lust and he talked about people getting out of control with their sexual behaviour. And there should be nobody in the christian church who should be in any way abusing anybody sexually. That is against the teaching of the church, that is against basic biblical understanding.

Now, abuse can be all kinds of things. It can be manipulation, it can be asserting power over people.

Do not take advantage of a brother or sister. Just stop and think about this for a moment. When Paul wrote that that was a really, really radical thing to say. He's writing at the time of the Roman Empire, when abuse of women and slaves was commonplace, for Paul to say, do not take advantage. He was trying to say that christians should be characterised by a love of each other, which may be within the sexual relationship, within marriage, but it may be more generally as well.

It should not be about taking advantage of each other. True love is not marked by power, but in giving surrender and finding the good for the other that you love. True love is not about power.

Just over a year or so ago, there was a movie that I went to see called women talking. It is based on a novel by a lady called Miriam Choez. But Miriam Trowers took the idea from something that actually happened, so she transferred it from South America and put it right in the middle of middle America. It is about a group of women, christian women, who belong to the amish movement. And what had happened in the real story and in the novel was that these women had been systematically abused sexually by the men in the community who had tried to justify themselves.

And then when they couldn't justify themselves, they sought forgiveness. The film is really the women's debate about how do they deal with this situation where men really don't understand what forgiveness is, that they think it will just get them out of their problem when they have done any unbelievable damage to the women in the community there, by the way they've treated them sexually. And what is fascinating about the film is just how true it is to the gospel that all of the debate these women are having is about what is truly loving and what isn't truly lovely. Now, we are called to make sure that in our relationships we are not a church or a people who are characterised by bullying, manipulation, undermining each other. And that's particularly true in marriage, where those things can happen.

Purity of heart, according to the thinker Soren Kierkegaard, was to be able to will one thing and to do it. In other words, to commit yourself to one course of action and to do it now. If I want to be holy in any aspect of my life, my will is not enough. My will is not enough, but the power of God is.

So wherever you are today, whatever your struggle might be, whatever your temptation is, I want to say that forgiveness is available, but it does come at some cost and it depends what you need forgiveness for. Okay? So you may need to talk quite long and seriously. It may be something that can be fixed very straightforwardly.

Vaughan Roberts, writing in his book distinctive says this, we all fall short of God's standards in thought, word and deed. For some, the struggle is in the whole area of the thought life. For others, the challenge is something that you're doing physically, which you know is wrong, whether casually or with another person. If we're asking how far can we go, we're asking the wrong question. Purity is really difficult for us in a world that is obsessed with sex, where we can see images, watch things, read things that perhaps we should avoid.

But we go back to that story that I started with of the woman caught in adultery. He who is without sin, let him cast the first stone. That was Jesus challenge to the mob, bringing the woman caught in adultery. I like the comment that kind of refers to that in one of you two songs. Throw a stone in the air and you're bound to hit someone who's guilty.

Throw a stone in the air and you're bound to hit someone who's guilty. Each one of us may in some way be short of purity in this area. And it doesn't matter whether you're young, middle aged or old. This is not an age related sin. These areas can come at you and be difficult in your life at different points.

And we need to be honest before God and honest with each other. I strongly recommend, and it may not be tonight because it may not be appropriate tonight for you. But if there are areas that you are struggling with, seek someone out as quickly as you can, have a discussion with that person in the context of prayer and faith. So let me summarise. There is great strength to be had in marriage, but there are still temptations and difficulties there.

We need to support each of us wherever we are, whether we are married or unmarried. All of us have temptations. We need to remember that holiness is a body thing. It isn't just a spiritual thing. What we do with our bodies matters to God.

And as Christians, purity for us should be. We always value the other person. We do not take advantage. We look to God's leading and we live in the life of the spirit. Let's pray.

Father, we thank you for this challenge to us. This is really tough stuff. And just pray that it will help us to think through how we behave in these areas and to find the best way to live in the power of your spirit. Amen.