It’s striking that one of the earliest and most powerful images of Jesus Christ is that of a rock broken open, with water streaming from the cleft. It’s used by St Paul in I Cor.10 – looking back to the account in Exodus of Moses striking the rock in the desert so that the Israelites will have water to drink. And every time we see a font for baptism in a Christian Church, there is a faint but significant echo of this image: stone and water, a cloven rock with a stream rising from within it.

A rock: Christ the foundation stone, Christ the abiding, solid presence at the base of all we build. Certainly that’s part of how St Peter in his first letter encourages us to think. Being baptised is finding a foundation, and where else should we find it except in the absolute consistency and faithfulness of God in Jesus Christ? Everything else may change but this won’t: on this rock, lives, communities, hopes and possibilities can be built with confidence. For someone being baptised, for those being baptised this afternoon, what is happening is that the promise made by the Risen Christ to be there for them until the end of the world, or to the limits of the globe, is made by name to this or that specific person; one more unique reflection of Christ’s glory and love begins to be shaped and nourished into life by being anchored to the unchanging self-consistency of God.

A rock, but also a rock dramatically broken open: there’s a paradox. A rock that is a sign somehow of vulnerability at the same time as stability, flowing, mobile water running out and over the stone. Because God’s faithfulness to his promise is made known to us in a set of events that can only be compared to the rocks splitting apart and the fabric separating the world we know from the world of God’s holiness being torn in half. When St Matthew describes the death of Jesus, that is how he does it: earth and heaven both being torn, as though the terrible wounds in Jesus’ crucified body are a wound in reality itself. And as the blood and water streams from the broken body of Jesus – to use the imagery of another gospel – we see the indestructible solidity of God’s love within this body, which will begin to move so as to break open the rocky prison in which that body is buried. Another broken stone, another wound in the world, and out of it pours the restored life of Jesus and the light of the new creation for all of us.

God is who he is, stably, eternally, dependably, the rock of ages; and it is in the life and death of Jesus of Nazareth that we see this stability living in and through the horrors of the human world where human beings reject and torture one another and hate the light. The rock is split open by sin and death, and out of it comes another and dramatically different sign of unfailing stability, the unstoppable waters of a flood that nothing can turn back. Ezekiel’s vision of the restored Temple, where water pours out until it is too deep to wade across: a stability, yes, but one that you have to abandon yourself to in trust. So that the obvious security of the rock is also a call to let yourself go into the water and be carried by its irresistible current.

As you can see, once you start on rocks and water in the Bible, you realise that they’re everywhere. Throughout the Old Testament narrative, God leaves swathes of clues in the shape of one image after another that weaves together the themes of absolute stability and the irresistible flood of divine action. God is, in the poet’s words, ‘still, and still moving’. As soon as we think we have got clear in our minds the idea of a God who doesn’t change and can always be trusted, we are reminded that his stillness and steadiness are at the same time a vortex of energy, uncontrollable and unstoppable. To be brought into relation with God is to be brought to our home, where all restlessness and questing stop, and also to be brought into ceaseless movement towards unknown depths. Our life of discipleship is a blend – sometimes bewildering, sometimes exciting – of utter confidence in the rock of ages and the disturbing knowledge that this rock is ‘cleft for me’ and that the streams running from the wounds of Christ will carry me to places I might not have chosen to go.

The early Church was insistent that baptism be performed in running water – ‘living water’; our usual practice of sprinkling a few drops from a bowl would have looked slightly anaemic to them, I suspect, losing sight of the symbolic force of water that genuinely has a life of its own and can sweep away what’s in its path. But at any baptism, what we most need to bear in mind is that one fragile life is indeed being linked to a life that is not its own, to eternal life, Christ’s life; the gift of the Holy Spirit in baptism is the gift of communion with what is both unchanging and uncontainable, the same life that split the rocks of Calvary at the crucifixion and moved the stone at the mouth of Jesus’ grave. So that the life we now live in Christ, immersed in this stream of truth and energy, is a life that is deeply secure – but always encountering new risk and challenge. For us to be Christians is for us to know the rock of anchorage at the heart of everything, but also to risk being broken so that life can continue its flow. It is about being where God is and about God being where we are. In baptism we are re-created to be places where worlds intersect – the world of eternal and victorious love and the world of chaotic, reactive, fearful relationships. Where we are is now a place where the fabric of this latter world is being disturbed by the current of something deeper; the baptised person is dangerous to be around because the fountains of the deep may burst through. What is asked of us is to stand our ground in trust: we shan’t be kept from wounds any more than the Son of God was spared his wounds, but we can be sure that our place is his and his is ours if we will simply rely on his promise.

A lifetime’s work. Today we see that work beginning in two young lives, and we all commit ourselves to nourish those lives in the trustfulness and confidence they need. And as we bless this great new sign in the midst of this cathedral, we ask God to keep our minds and hearts steady and faithful – our foundations on the rock of Christ, our spirits and bodies alive with the unstoppable flow of the life that pours from his cross and empty tomb.