One of the most moving stories in the Gospels is told in Luke 7:36-50. Luke tells us of how Jesus was invited to the house of Simon, a Pharisee, and a sinful woman came in and wept, poured perfume on his feet and wiped them with her hair. Even today there's something shocking, almost indecent, about the picture. It's nakedly emotional, and would have been regarded – then as now – as fatally compromising a respectable religious person in the eyes of the onlookers. So Simon the Pharisee is probably being quite generous when he thinks: "If this man were a prophet, he would know who is touching him and what kin of woman she is – that she is a sinner." At least he assumes Jesus didn't know who she was.

But Jesus compares their behaviour to his disadvantage: Simon, not at all impressed by this wandering teacher and miracle-worker, had barely been courteous, while the woman had been extravagantly generous.

The difference, he explained, lay in what they owed.

The best way to understand this story fully is to realise that it was not, in fact, the first meeting between Jesus and the woman. For the story to work it's likely that they had met before. There was an encounter in which Jesus recognised her sinfulness and offered his forgiveness, perhaps telling her as he told the woman taken in the act of adultery in John 8:1-11, "Go and sin no more."

Simon had probably never really done anything wrong in his life, while this unnamed woman lived every day with the knowledge of her unworthiness. He related to Jesus as his superior; the woman was profoundly grateful that she had been forgiven. She came to him in the house of Simon to make a public demonstration of her gratitude.

We misunderstand the story if we think Jesus means, when he says in verse 47 that "her many sins have been forgiven for she loved much", that her sins were forgiven because she loved, as though it's cause and effect. He means we know her many sins have been forgiven because of the extent of her love in response.

It would be foolish to say it's better to be a sinner than it is to be a saint. No one who has done wrong is glad to have done it. But doing wrong, really understanding that you've done wrong and being forgiven for it, is a great gift. The sinner knows how much he is loved because it's been proved.

We should not look down on people who are weak, or foolish, or unfortunate, or criminal. Because Jesus turns the world upside down; and they're the people who have more capacity for love, because they've had love shown to them. When it comes to the kingdom of heaven, respectable people should know their place.

Follow Mark Woods on Twitter: @RevMarkWoods