This is a post for people who don't understand why Christians are always arguing about sexuality. To be honest, we're not always arguing about it - I devote a fairly small amount of my time to arguing in general, only a small chunk of that to arguing with other Christians, and a relatively ickle proportion of that arguing about sexuality - but it does get reported a lot, and not just in the fake news. I want to explain to people who don't know Christianity from the inside why it is that we Christians are having an argument over something that most people think is a matter entirely for individual consciences, where it isn't so blindingly obvious that anyone ought to see it. I'm not going to particularly argue for a position. This is just an introduction to why we feel the need to take up a position in the first place. It may be patronising, in which case my apologies. It's just some stuff that to me seems to get missed in the translation of inter-Christian arguments into the secular press.
So here goes.
First thing to note is that Christians believe that everything has meaning. This is based on the notion that ultimate reality is personal (God), and that every part of contingent reality (i.e. everything else) stands in some sort of relationship to that ultimate reality, and that relationship defines what this particular part of contingent reality is all about. This is very different from a view of reality as ultimately meaningless. Meaningless is what everything ultimately is if, at bottom, there is no personality. There are two ways of thinking about an ultimately meaningless reality - the optimistic way and the pessimistic way. If you take the optimistic route, you will think that the ultimately meaningless reality is like a blank canvas, onto which we can project whatever meanings we like; we are meaning makers. If you go down the pessimistic road, well, meaningless is meaningless. Perhaps the best we can do is live with some sort of authenticity, but even that is, at the end of the day, without meaning. We are lost, accidentally endowed with a desire for meaning and incapable of genuinely finding or making anyway.
If everything is ultimately meaningless, whether you are optimistic or pessimistic about our ability to make some sort of meaning within that, it is obviously a waste of time to argue about what things mean. Either it's like arguing about which flavour of ice cream is best - it's clearly a personal choice - or it's like arguing about whether cheese is snurg - it's total nonsense. But if reality is at bottom personal, and if contingent reality therefore has meaning, it may be possible to find meaning in each part of contingent reality - by which I don't mean some variation on the optimistic view above, where I project meaning into something, but something more like digging for gold: there might actually be meaning in there, and I might find it. And in that case we can have a genuine conversation about what it is that we've found: we could argue about what something means, and it wouldn't be obviously nonsense.
Second thing is that Christians believe in revelation. In the Christian context, that means one particular thing (and lots of other things which depend in one way or another on that one thing). It means that we believe that the ultimate reality - the personality at the bottom of it all, by relationship to whom the meaning of everything else is defined - this ultimate reality has appeared within contingent reality. This has a pretty substantial effect on the quest for meaning. If it's true that the meaning of contingent reality comes from its relationship to ultimate reality - well, that might mean that everything has meaning, but it wouldn't necessarily mean that we could discover what that meaning was. In fact, it seems unlikely that we would discover it. The sort of ultimate reality we're talking about it transcendent, which is to say that although it undergirds all of contingent reality, it does not appear in the way that contingent reality does. If you catalogued everything in the universe, ultimate reality wouldn't appear in the catalogue, because it is what stands behind and beneath everything else.
But the claim is that ultimate reality has appeared in the midst of contingent reality, and in fact has appeared as contingent reality in some sense. Of course, what Christians are referring to is the incarnation, the idea that the God who stands behind everything became a human being - became the Jewish carpenter and itinerant preacher Jesus of Nazareth - and lived and died in our world, in our history, at a point on a normal map that I could point to right now. If that is true - and that of course is a huge if - then the story of Jesus of Nazareth is the centre point around which everything else revolves. If everything in contingent reality derives its meaning from its relationship to ultimate reality, and if ultimate reality is revealed in the life story of Jesus of Nazareth, then the meaning of everything in contingent reality can be seen in its relation to this life story. That is a great big claim, but for the Christian it means that the question of what everything means is not a vague philosophical one, but a concrete and yet very personal question about what this particular chunk of contingent reality has to do with Jesus. That is something about which we could argue, you see, because there is an answer, and the answer is not in principle hidden away.
Thirdly and finally, what does this have to do with sexuality? Well, in the general sense, obviously human sexuality is an aspect of contingent reality, and so we can ask what it means, and we can try to work out the connection between it and the life of Jesus, just as we can for every single 'thing' in the universe. But there is something more specific than that. We've already said that the Christian thinks that reality is ultimately personal, and indeed relational. That makes human beings uniquely important - apart from angels and demons (which are a complex part of the Christian view of the world) we are as far as we know the only contingent personalities in existence. And it makes the relational aspect of human beings particularly significant. We could view the fact that ultimate reality became human in Jesus as the confirmation of this particular importance and significance. But sexuality lies very near to the heart of who we are as relational persons. Which should lead us to expect that when we are talking about sexuality, we are talking about something that is absolutely charged with meaning.
That is what we are arguing about, and that is why the arguments are heated. For Christians, sexuality has meaning, and its meaning stands in close relation to ultimate meaning. The Bible - which for Christians is the first and authoritative record of God's communication to the word, and therefore the means of his communication to the word in the present - suggests that human marriage, particularly in its sexual component, is a picture of the ultimate story of reality; the story of God's coming into the world in Jesus to unite humanity to himself in loving relationship. So the nature of our understanding of sexuality is closely related to our understanding of God. There is meaning, really important meaning, in there. So we discuss it.
There's rather more to say than that, and of course I take a definite view of where the discussions (or perhaps better, arguments) ought to end up. But I hope that helps to explain why we're having the discussion in the first place.