Cat, meet pigeons.

We're just hours away now from the end of the incredible circus of the American elections. (And if you're American, and eligible to vote, and it's currently November 4th, what on earth are you doing reading a blog instead of voting?) It's been quite a ride, and hopefully soon we'll know, one way or another, who's going to become the most powerful man in the world.

The Presidential vote isn't the only thing decided by the polls tomorrow. There are Senate seats, House seats, Governorships and all manner of other things up for grabs across the country. And, in some states at least, there have been initiatives to use the fact that people are voting anyway to do state-wide referendums (referenda?) on various issues.

The most publicised – and most controversial – of these issues is in California, where Proposition 8 seeks to make it unconstitutional for gay people to get married in the State, or for their out-of-state marriages to be recognised. Literally millions of dollars have poured into this issue, on both sides, as emotions (quite understandably) run very high. It's the kind of thing you might want to stay out of, really.

Unfortunately, that's not an option. Like it or not, gay people are here to stay, and the question of what we do about their wish to marry is pretty nearly central in the issue of how our society treats them. Because of that, it's an issue that is not going to go away. More importantly, it's something that you can't avoid having an opinion about, because sooner or later someone will ask you what you think, and when they do a shrug and a "meh" just will not pass muster.

Why? Because gay marriage is an issue that cuts deeply, on both sides of the argument. To those who oppose it, it's part of their core beliefs, part of the morality that defines them. For those who support it, nothing less than a key civil right is at stake here, something worth marching for, something worth protesting about, something worth sacrificing time and money and even personal safety to support. That means that indifference, honestly felt though it may be, will be seen as horribly offensive by both sides. We're too far in for anyone to be able to opt out.

For Christians, the problem is even harder, because two conflicting principles are at stake. How do we show to everyone that we love them in the same way that Christ loves them, while also getting across that Christ is also in charge of the way we live our lives? Is there a way of truly accepting everyone, just as Jesus did, while at the same time holding firm to his more difficult teachings? And, cheesy quotation it may be, but what would Jesus do in this situation?

I'm once again going to have to wheel out my disclaimer at this point. For the most part, I don't bother saying "I think" or "I believe" on this blog, because if I'm writing it then obviously I think it or believe it, and there's no point in qualifying it like that. In this case, though, the issue is so complex that I cannot possibly claim to have the last word, and though I stand behind everything that I say here, your mileage will almost certainly vary. Oh, and I can tell this is going to be an incredibly long post, even by my standards. OK? Good, on we go.

One of the main problems when discussing this issue is that everyone uses the same words, while actually meaning a number of different things. In an attempt to avoid this, let's go through some of the key principles and concepts in the debate.

First, what do we mean by "marriage"? By that, I don't mean "is it one man and one woman", I mean "what does each side actually mean when they use the word?" Let's start where we have to if we're going to do the Christian side of the argument properly – let's go to the Bible.

The Bible talks about marriage quite a lot – the word (or close variants) appears 200 times in the NIV – but very rarely does it actually define the concept. It doesn't often happen in a church or temple, marriage vows are hardly ever mentioned, wives are sometimes bought, sometimes kidnapped and sometimes simply given away, men can decide to divorce their wives at any time (in the Old Testament, at least), polygamy is common (Old Testament again), and frankly it's a bit of a mess all round. Things start to get clearer in the New Testament, where we're told that leaders of the Church are to have no more than one wife, and that they are to stay faithful to her alone, but even there we see no sign of a ritual or ceremony.

In fact, the only principles that are always spelt out is that God really does not like it when marriages end. Very rarely does the Bible ever say that God hates anything (this is a notable exception), but Malachi breaks with this in an extremely blunt way:

"I hate divorce," says the LORD God of Israel, "and I hate a man's covering himself with violence as well as with his garment," says the LORD Almighty. So guard yourself in your spirit, and do not break faith. Malachi 2:16

It's pretty clear, then, that whatever form marriage takes, it's important to God and it shouldn't be taken lightly. I find it interesting that the kind of person who will write to the newspapers, green ink flying and frothing at the mouth, whenever a gay couple kiss on screen, will not bat an eyelid when adultery is routinely and casually portrayed. Which one has an entire commandment to itself?

So, from the Biblical perspective, marriages are a good thing, to be taken seriously, and otherwise not very well defined. What about from the world's perspective? Well, leaving out the "financial gain" and "spur of the moment" motivations, marriage means two things: a public declaration of faithful devotion, and a way of legally recognising a partnership that already existed in all but name.

Now, is it just me, or does it actually matter whether or not these are served by the same mechanism? After all, a Biblical marriage (whatever it is) is one whether or not the government says it is; likewise, signing the papers does not produce a Biblical marriage if the participants have no intention of seeing it as being forever.

This means that my answer to "do you support gay marriage" would, in an ideal world, be the following: legal marriage and religious marriage should be entirely separate concepts. The legal aspects (allowing people to hold property jointly, inheritance, visiting rights in hospitals, joint bank accounts, the whole shebang) should be available to any two people who want to use it. We already have a name for such a concept – "civil partnership". Currently this concept is practically synonymous with "gay marriage" in the UK, but all it would take would be expansion of its availability. Once a couple were legally "civil partnered", they could arrange whatever kind of ceremony they liked to recognise it in their faith, or among their friends, or whatever they liked. Immediately, Christian marriages would no longer be devalued by association with the marriages of convenience we see nowadays, because only people who actually cared about them would go in for one; likewise, supporters of gay marriage would have all the benefits, and could call it whatever they liked.

There are two problems with this idea. The first is that it'll never happen. The idea of a "church wedding" has become so deeply ingrained into society that it's seen as the "right thing to do", regardless of the fact that a lot of the people who have one have absolutely no intention of following Christ, and they will see it as being unfairly shut out. The second problem is that answering "do you support gay marriage" with "I want to split up the concept of marriage entirely" doesn't actually answer the question.

So let's answer it, in a very carefully-defined way. Question one – should churches bless gay unions and call them marriages?

There is no point in saying that you believe the Bible to be the word of God unless you're prepared to accept the whole thing. Doesn't mean you have to accept it all as literal truth, doesn't mean you have to understand it all, but it does mean that you can't ignore bits you don't like. And it is very clear that God does not approve of active sexual unions outside the context of marriage. Even accepting that marriage is very sparsely defined in the Bible, multiple verses – Hebrews 13:4, 1 Corinthians 7: 1-3, and Matthew 5: 27-28, to give a few examples – state very clearly that sex outside it is, to put it mildly, a seriously bad idea, and that includes homosexual sex. It doesn't mean that people who are attracted to those of their own sex are inherently evil, any more than it would for those who are attracted to a certain accent or skin colour, but it does warn against acting on that attraction. For this reason, I don't think a church should bless the union of any couple – heterosexual or homosexual – who are sexually active outside marriage. Welcome them as God's people, yes; love them as Christ would, yes; ask God to look favourably on their actions when you know full well he does not approve of such actions, no.

On to question two, then: should the state recognise legal unions between gay couples and call them "marriages"?

Although it's not an explicitly Christian question, as a Christian I'll have to answer it from that perspective. We've already seen that Christian marriages have very little to do with the world's view of marriages, hetero- or homosexual. Now let's add in the fact that you can't achieve salvation by what you do.

For any of you who are not familiar with this concept, it basically goes like this: humans are sinful. We all do bad things, not a single one of us is perfect, and because God is perfect, none of us is worthy to join him. Because Jesus was perfect, we can use his perfection and his sacrifice (when he died on the cross) to allow us to meet with God. This cuts two ways – nothing bad that you have done can disqualify you from becoming a Christian (because no-one was good enough anyway), but on the other hand no matter how good you try to be you can't reach God by yourself. Anything "good" that Christians do, therefore, is not an attempt to make God save them – it's a response to the fact that they have been saved.

This means that the kind of person who marches around saying that "gay people are SINFUL!" (I'm looking at you, Westboro Baptist Church – don't Google them, you'll just get depressed) is massively missing the point. Expecting non-Christians to abide by the rules that Christians follow is daft, because they haven't been saved. If they can't reach God by their actions, then "stopping being gay" (if such a thing is even possible) isn't going to help a lot. A Christian's focus should be on reaching out to the world and loving it, telling people that there is a way to God – let their lifestyles change after that point. Trying to make people sit up straight and smarten themselves up before you get on to the "God is amazing and he loves you" bit is not going to get you anywhere, and is completely antithetical to the way Jesus worked.

All of which is a pretty convoluted way of saying that because telling non-Christians to follow Christian rules is ridiculous, trying to change any kind of non-Christian marriage to look like a Christian one is also doomed to failure because even at best it will be a sham. As such, we can't try to use Biblical arguments to control a marriage that was always going to be non-Biblical. And this means that the question before us should really be answered in terms that don't directly use Biblical arguments. Let's look at the issues that fall under this remit.

Does calling a gay union "marriage" devalue heterosexual marriages? No more so than heterosexual couples have already managed. We already have marriages of convenience, marriages that last mere days, people getting married in Vegas because they were really drunk and it seemed like a good idea at the time; frankly, letting in some people who are going to take it seriously can only improve the situation.

Will gay marriages cause society to crumble? They haven't so far. The UK is yet to implode, as is California (yes, Proposition 8 aims to take away a right that gay couples already have).

Doesn't this open the door to people marrying animals/trees/robots/fourteen other people? No, because those people are generally known as "completely insane" and there's hardly any of them. Let me know when the first "man-dog love association march" happens in San Francisco and then I'll start to worry.

Does allowing gay marriage lead to a better quality of life for gay people? Undoubtedly yes. Allowing gay couples to marry grants them all the same legal rights as heterosexual couples, which is really quite a lot. Anything that raises quality of life without causing society to implode (see above) and which does not cause Christians to disobey God's laws (see further above) is a good thing.

So, really, allowing gay couples to marry (in a non-Biblical sense) has positive effects, and no negative effects other than people saying "calling it marriage makes me feel icky". To which the only response is, grow up. And does the measure on the Californian ballot force churches to bless these unions? No. Does it make Christians give their support to such unions? No. Does it help people? Yes.

Let's summarise. Christian marriages and non-Christian marriages aren't the same thing anyway. Non-Christians can't be expected to act in the same way as Christians, because they haven't experienced the same things. And gay marriages are explicitly in the non-Christian marriage category, which is what the ballot initiative is talking about anyway.

Let's summarise even further. Hi. My name's Phil. I'm a fairly conservative evangelical Christian, and I support gay marriage.