Jesus said: "From the beginning of creation, 'God made them male and female'." (Mark 10:6)

I have a problem with weddings. This is a bit of an issue, given that I am a church minister.

In particular, I struggle with photographers who seem determined to turn religious services into celebrity magazine-style photo shoots. And more than that, I worry about the costs involved. Many couples getting married these days seem to spend vast amounts on their wedding day in the belief that everything has to be "just right".

So it is a relief to turn to the words of Jesus about marriage in Mark 10. Every time I read these verses I remember that the following (in no particular order) are in no way mentioned by him at any stage: white dresses, ushers, best men, confetti, bridesmaids, rings, hats, vintage cars, printed orders of service, bouquets, banns, registers, receptions, honeymoons, discos, speeches and very tall men who seem to stand at the back of every wedding service I take and eyeball me while refusing to sing. Oh, and did I mention photographers?

Frankly many couples could jettison a lot of the costly stuff and still have just as much fun on the day. It's probably a lot of the exorbitant wedding paraphernalia that has, at least in part, led to the rise in cohabitation.

So how does Jesus define marriage – and thus how should we? The answer is, "very simply". Jesus says marriage:

1. ... is between a man and a woman. He points back to the first book of the Bible, to God making humans male and female, and says that "for this reason a man shall leave his father and mother and be joined to his wife, and the two shall become one flesh" (v7).

2. ... is God's idea. When a couple get married, Jesus says, "God has joined [them] together," (v9).

3. ... is meant to be permanent. Once a husband and wife are joined in marriage, "let no-one separate" them, he declares (v9 also).

Simple? Yes. Simplistic – no. Because actually each of those things are hugely profound, with so much packed into every little phrase. At the same time, many people might feel a lot of questions are left begging: What about same-sex couples, divorce, domestic violence, forced marriages or cohabitation? There is far more to be said about these issues than space permits here. But what we can say briefly is that:

Whereas Jesus often crashes through tradition, here – by contrast – he tightens it up. Jesus was happy to shatter taboos on numerous occasions for the sake of the Kingdom. But here, actually, he does the reverse, declaring that Moses had only permitted divorce because of people's hard hearts (v5). Far from taking the opportunity to loosen up the cultural norms of his time, Jesus says they need to be stricter. If Jesus was going to re-define marriage in the way many today are seeking, here was the ideal opportunity. We might really wish he had; but he doesn't.

On the other hand, we are reminded that many of the ceremonial things by which a lot of people define weddings are nothing to do with what Jesus says. If we're going to re-define marriage, let's get rid of the costly clutter!

It's no coincidence that Jesus then immediately talks about children after he has spoken about marriage and divorce (v14-16). This is not accidental. Marriage failure can devastate children. As Bishop Tom Wright has written: "Which is kinder, more Christian: to say that these things [marriage and divorce] don't matter, or to take a strong line, like Jesus, on behalf of the truly weak and vulnerable?"

Ultimately, Jesus says, the heart of our problem with much of this is the problem of the human heart (v5). And it is here that what can seem like a clash (in the eyes of some) between the rigidity of Jesus' teaching, the reality of messy human lives and the radical nature of Jesus' inclusive gospel find their resolution. For often we seek in human relationships what only God can fully provide. When I read out Banns of Marriage in a service I pray for the couple who are preparing for their wedding and then sometimes add a further brief prayer incorporating words of St Augustine: "And for all of us, whether married, single, separated, divorced, bereaved – and whatever the desires of our hearts – may we find our rest in You O Lord; for 'You have formed us for Yourself, and our hearts are restless till they find their rest in You'. Amen."

David Baker is a former daily newspaper journalist now working as an Anglican minister in Sussex, England. The Rough Guide to Discipleship is a fortnightly series.