The audacity of Christian art: This world and the next: Christ on earth; Christ in heaven | National Gallery

In the past two episodes we've seen how artists have played with our sense of place and time to draw attention to the paradox of Christ's being a human, living an earthly life and dying an earthly death, and also divine; beyond the limitations of time and space. But there are many images that go even further in detaching themselves from a particular, identifiable place, or moment in time. In this painting by Jan Provoost, made in the early 16th century, we see Mary and Jesus sitting in a garden with a landscape beyond. They're wearing beautiful clothes and jewels, and the garden wall which they're sitting on is covered in plants and flowers like the millefleurs tapestries of the time. She is holding a posy of flowers, he is holding a child's toy - a little spinning top. In the background is a landscape with a farm and little figures carrying everyday objects. A jug over here and a basket of logs here. There's no gospel basis for this scene - no description of Mary and the baby Jesus sitting in a garden. So what are we to make of it? Well, we're being invited to consider the relationship of Mary and Christ to Adam and Eve. The garden with all its flowers is a reminder of the paradise that was lost when Adam and Eve were expelled from the Garden of Eden because of their disobedience. Mary and Christ become a Second Eve and a Second Adam who repair the damaged relationship between mankind and God. In a sense, the Virgin herself is Paradise. She's the pure material from which new life springs. This paradise imagery continues. Behind the Virgin is a tree, which reminds us of the Tree of the Knowledge of Good and Evil in the Garden of Eden. And in a more sinister way, if we look closely, we can see a little stem of thorny brambles. This might make us think of the crown of thorns which Jesus will wear at the end of his life. But it's also a reminder of the serpent which tempted Eve, and which was punished by God. Look how it creeps across the ground there. In the background the landscape looks attractive but the people there are working hard. They are still labouring under the old order. So we have the paradise promise of the garden, and the harsh reality of life as it still is. There's a promise of redemption, of a new creation, but it's a future hope: human labour continues. And there are reminders of Christ's sacrifice, too, of the things that will happen before anyone gets to heaven. The fence of the garden is a series of rough posts nailed together. We might think of the rough wood and the nails of the Cross. There's a cross bar pointing diagonally towards the Virgin and Christ, like a spear: we might think of the spear used to pierce Christ's side after his death. And there's a pot of carnations, inside its own miniature fence. Carnations are a symbol of divine love, but also of Christ's suffering. The little fence of stakes holding the plant upright even has a little crown of pointed finials. Crowns and suffering. So in one painting we've got Paradise, life on earth in the background and a view ahead to Christ's Passion and its redeeming effect. Images of the Virgin and Child enthroned have a similarly complex relationship with time and place. Like the Virgin and Child in the garden, they explore the humanity and divinity of Christ. This painting by Cosimo Tura, made in the 1470s, is another scene that has no narrative counterpart in the gospels. Mary and Christ were not literally enthroned during their earthly lives. So they must be in heaven. Tura's setting is clearly heavenly. Not only are there angels playing music, but the architecture is completely fantastic and we can see celestial blue sky both above and below them. But what is the infant Christ doing in heaven? Surely in heaven he would appear - if we can put it that way - in his adult, resurrected, form. The throne must be heavenly but the baby seems to belong on earth. Tura's elaborate setting suggests a world beyond the dimensions of our own, but some images go even further in confounding our sense of time and space. We're back in the Conservation Department to look at this depiction of the suffering Christ by the 15th-century Netherlandish painter, Dirk Bouts. It's a fine example of a very popular type of painting made for religious contemplation. And it is deliberately distressing to look at. We see Christ naked beneath a red robe, crowned with thorns and marked with the wounds of the Crucifixion. But with his eyes open and his hands raised. Christ wears a robe and the crown of thorns before he is nailed to the Cross. The robe is removed, the thorns remain. Here we see both. But this isn't Christ before the Crucifixion, because we can see the nail marks and the wound in his side tells us that he is dead. He's still wearing the crown of thorns, but his eyes are open. The background is golden - heavenly perhaps - and a red robe can be associated with the Resurrection. But this isn't in any usual sense an image of the Resurrected Christ. As a single moment, it is impossible. As a combined image of Christ's human suffering, of his endurance unto death and his divine capacity to overcome it, it is extremely powerful. The temporal and spatial ambiguity of the image - the suggestion of it being both of this world and of the next and yet somehow of neither - invites us to reassess our sense of how things relate to each other over time and over eternity. And it encourages us to contemplate the mystery of Christ having a temporal life on earth, and yet being part of the eternal Trinity.