In the furore over the introduction of same-sex marriage in the US and UK, evangelical Christians have been keen to stress the importance of 'biblical marriage'. But now that same-sex marriage is here, isn't it time to look again at what biblical marriage really looked like, and to learn some life lessons for today?

1. Abraham and Sarah

As well as being a great Bible hero, the first of the patriarches was a deeply flawed individual who on two occasions (Genesis 12:10-20 and 20:1-18) passed Sarah off as his sister (in fact she was his half-sister) and allowed her to be courted by powerful men because he feared for his own life. He also had a child by her slave girl, Hagar, because he did not believe that God would give him a son by Sarah as he had promised.

Those were different days, in which women had few rights and much lower expectations. But these Abraham stories make uncomfortable reading. They show us someone who was entirely self-centred, with no concern for his wife's feelings, putting himself first no matter what it did to her. It's no pattern for a good marriage – but sadly, it's what many marriages are like. Selfishness like this isn't part of God's intention.

2. Elkanah and Hannah

Elkanah had two wives, Hannah and Penninah, which was normal at the time, if the man could afford to maintain them. Their domestic tragedy was that "Penninah had children, but Hannah had none" (1 Samuel 1:2) and Penninah made Hannah's life miserable because of it; infertility was a heavy burden in biblical times, because it was seen as a sign of God's disfavour. In the end, Hannah becomes pregnant with Israel's greatest judge, Samuel. Her story ends well. But we should spare a thought for Elkanah. Instead of casting her out, as he would have been entitled to do, he does his best to comfort her: "Why are you downhearted? Don't I mean more to you than 10 sons?"

It's rather clumsy, but his heart is in the right place. He assures her of his love and respect whatever her perceived failings. His love is unconditional, and that's a rare and precious thing.

3. Nabal and Abigail

Nabal is described in 1 Samuel 25:3 as "surly and mean in all his dealings". Though he was a rich man who had benefited from David's protection, he refuses David's request for provisions for his men and insults him. David loses his temper and resolves to kill every male in his household. Fortunately for Nabal, he has a wife who is far wiser than he. Abigail loads the family donkeys with vast quantities of food without telling him and takes them to David, urging him to avoid "the staggering burden of needless bloodshed" (v31). Nabal comes to a bad end; when Abigail tells him what she's done, he appears to suffer a stroke and dies. David takes Abigail as one of his wives, an arrangement that seems to suit them both.

Women in the Bible are often victims, but not all of them. The Bible affirms women's initiative, courage and wisdom. Here it's the man of the house who is inferior to his wife on every level. It is a lesson in humility.

4. Ahab and Jezebel

In many ways, Ahab was quite a successful king. However, he "did more evil in the eyes of the Lord than any of those before him" (1 Kings 16:30). He also married Jezebel, a Baal-worshipper, which was one of his worst decisions. She failed to understand the limits of an Israelite king's power and when Naboth the Jezreelite refused to sell Ahab his vineyard she took matters into her own hands. Jezebel arranged to have him judicially murdered (21:9) and Ahab took possession of the vineyard. The prophet Elijah makes it clear where the responsibility lies: both of them are to blame.

Marriages are intimate relationships which shape both of those involved. A husband or wife can make a spouse a better person, or a much worse one. We have a responsibility to be the best we can be, not just for our own sake but because of how we affect someone else. And if we're considering marriage, we need to ask ourselves: how will being with this person change me? Will it make me better, or worse?

5. Hosea and Gomer

The prophet is told to "take to yourself an adulterous wife and children of unfaithfulness" (Hosea 1:2). It's a metaphor for God's relationship with Israel, which continually breaks its covenant relationship with him. Just as God continually forgives, so must Hosea: "Go, show your love to your wife agan, though she is loved by another and is an adulteress. Love her as the Lord loves the Israelites..." (3:1).

The extreme example – which there is no reason to think doesn't reflect events in the prophet's own life – makes a theological point, but it also makes a very human one. Infidelity represents a terrible betrayal, and many marriages don't survive it. Nevertheless, if the metaphor works in one direction, it can work in the other as well: if God can continue his faithfulness in the face of Israel's unfaithfulness, human beings too can forgive and restore their relationships. We are not God, and it is not always possible, but the story of Hosea and Gomer offers hope.