Nativity scenes are the art we see at Christmas, often on cards that put a masterpiece on the mantelpiece. Baby it’s cold outside, so let’s warm our hearts with a bit of Piero della Francesca or Bruegel.

Yet we close our eyes to the reality of this art. We turn Renaissance and baroque paintings into empty kitsch when we appropriate them as part of modern Christmas celebrations, which in truth have little in common with the much more religious world that created these images.

Look a bit harder and the great paintings of the nativity story that we sentimentalise at Christmas are full of death and decay. Some are are literally apocalyptic. Far from soppy, painted equivalents of a modern school nativity play, these paintings are premonitory visions of suffering that invite the most serious of meditations.

The Adoration of the Magi (1481-2) by Leonardo da Vinci. Photograph: Leonardo da Vinci/Getty Images/Art Images

The world is ending. It is in ruins. A civilisation is collapsing around us. That is the setting of Leonardo da Vinci’s Adoration of the Magi and many more depictions of the infancy of Christ. In Leonardo’s unfinished Adoration, the enigmatic ruins of wondrous buildings stand behind Mary and her child. Staircases lead to nowhere. Trees grow out of the crumbling structure. These ruins represent the decay of the classical pagan world. With Christ’s coming, the pagan age is over; its achievements – which Renaissance artists revered – must all fall into ruin. Leonardo goes further. He also depicts a distant cavalry battle to suggest the violence of history from which Christ has come to promise deliverance.

Other paintings show the ruins of Rome in a way that is eerie and bleak, suggesting that as well as hope, the nativity also brings a painful ending of old ways. As TS Eliot puts it in his poem Journey of the Magi, “this Birth was hard and bitter agony for us, like Death, our death”.

Caravaggio’a Adoration of the Shepherds (1609). Photograph: Dea Picture Library/Getty Images/DeAgostini

Eliot’s great, uneasy poem, about the pain as well as hope the Magi feel in seeing a revelation that leaves them uncomfortable in the “old dispensation”, is very close to the true spirit of Renaissance paintings. In Pieter Bruegel the Elder’s harsh portrayal of the three kings, they are exhausted old men, withered stumps of time, their myopic and senile faces unable to truly understand what they have seen.

Their gifts are troubling. Myrrh was used for embalming – it prefigures Christ’s death. Even without that clue, the fact that Christ has been born to suffer for human sins is not hard to see. In Leonardo’s Adoration, he reaches out to accept a gift as if accepting his fate. Part of the reason this painting is so potent as an unfinished work is that the uncoloured shadows evoke mortal thoughts.

Yet we don’t just ignore dark hints in paintings of the nativity – at Christmas we glide completely over a part of the story that artists in the past portrayed with the same insight they brought to the stable scene. You won’t find the Massacre of the Innocents on any Christmas cards, but it was painted as acutely as any nativity image by Bruegel, Rubens or Poussin.

Herod’s massacre of the firstborn does not fit our heartwarming image of Christmas. Unfortunately nor do nativity scenes, if we look at them with both eyes open. Caravaggio’s Adoration of the Shepherds includes a brilliant still life of a set of carpenter’s tools in the foreground. Is this just a nice allusion to Joseph’s job as a carpenter? Of course not. It is also a forewarning that one day such tools will be used to build a cross for Christ to die on.

Caravaggio includes a set of carpenter’s tools. One day such tools will be used to build a cross for Christ to die on

The seriousness of this birth is such that some artists simply shun cuddly domestic detail and portray it in an utterly sombre way as a moment of revelation. Piero della Francesca’s Nativity portrays Mary not nursing her child but kneeling on the earth to pray to and for him. The shepherds keep a respectful distance in front of a stable so humble and broken down that it places this mystical moment outside all human comfort. Only a choir of angels brings a silent music of joy.

The Nativity (1470-5) by Piero della Francesca. Photograph: The National Gallery Photographi/National Gallery, London

Sandro Botticelli goes even further. His Mystic Nativity sees the holy birth not in cute human terms but as the event that ultimately foretells the Last Judgment, the end of days and the coming of a new heaven and a new earth. Devils flee into hell as angels soar aloft.

Of course Renaissance and baroque artists find joy and hope in the nativity. Angels rejoice, dumb animals recognise the weight of this moment, and all eyes are on the child who will redeem the world. It doesn’t have much in common with the festive fun of our modern, highly secularised and commercial Christmas. These paintings are about death and resurrection and the shock of revelation. That nativity scene on a card is an opportunity for a moment of meditation amid the tinsel. More Silent Night than Jingle Bells.