The readings we have in church over Christmas are pretty well established. There are the shepherds and the angels, the wise men and the star, the inn and the manger. We will have Gabriel appearing to Mary, and perhaps – not invariably, in the circles I move in – we'll have Zechariah and Elizabeth too.

One passage that's never, ever read at the carol service is Matthew 1: 1-17. For most of us the Gospel begins at verse 18, 'This is how the birth of Jesus Christ came about...'

The first part of Matthew one is a list of names, a genealogy that takes the descent of Jesus back to Abraham. And why would anyone want to read that? It might have been interesting in the 1st century AD, but surely not now?

However: hidden in that list are four highly significant entries. They are, most unusually, women – and they are women with stories of their own.

In verse 3, it's Tamar, the mother of Perez and Zerah. Her story is told in Genesis 38. She was successively married to two of Judah's sons, Er and Onan, who both died. Judah went against custom by refusing to marry her to his youngest, Shelah, leaving her childless. Disguising herself as a prostitute, she slept with Judah himself. When he found she was pregnant he was furious and called for her to be burned. When she revealed the truth, he confessed, 'She is more righteous than I.'

In verse 5 we read of Rahab, the prostitute who hid the spies when they came to look over Jericho before it was attacked by Joshua. All the inhabitants were exterminated apart from her and her family. She became the mother of Boaz.

The same verse reminds us of Ruth, a Moabite married to an Israelite who followed her mother-in-law back to Israel when her husband died – and who married Boaz, and became the great-grandmother of King David.

Then there is Bathsheba, though she is not named but described as having been the wife of Uriah; she became the mother of King Solomon. Her story is well known: David saw her bathing on the roof, desired her and took her, and had her husband murdered. Whether she had much say in the matter has always been debatable.

The point, however, is that none of these women were classic Jewish heroines. They all had something againt them. Tamar resorted to unorthodox methods to get pregnant, compromising one of the fathers of the 12 tribes. Rahab was a prostitute. Ruth was a foreigner. Bathsheba was an adulteress.

And yet all of them found a place in the genealogy of the Messiah. Why should Matthew have chosen them to mention, rather than any of the other women in that long story?

In his book The Christmas Stories, Trevor Dennis suggests this. Matthew's account of the birth of Jesus focuses – as Luke's does not – on the shame felt by the unmarried girl and her future husband: 'Because Joseph was a righteous man and did not want to expose her to public disgrace, he had in mind to divorce her quietly' (verse 19). He has to be reassured by an angel that it's in order for him to marry Mary. Mary is in a long line of women who have been on the edge, who have taken risks with their lives and reputations, but through whom God has done great things.

The list that includes these women, he says, 'suggests that God is about to do a new thing and once more bring safety out of peril, honour out of dishonour, grace out of disgrace, good out of evil'.

Once we understand it like this, reading all of Matthew 1 packs a surprising punch.

'The Christmas Stories' by Trevor Dennis is published by SPCK.