Ash – so often a sign of destruction, of despair even. Justin Welby and Rowan Williams have written movingly of their experiences of ash in Rwanda, in New York on 9/11. The ovens of Auschwitz also come to mind. All experiences of ash without hope, ash as witness to human evil but with no promise of anything better.

But I would like to turn to another hero of mine, David Attenborough, for a different picture. “In the forests of Australia fire travels fast, consuming dry leaves and twigs. But the tree trunks are so tall and free from low branches that the flames do not reach the crowns of the biggest. After only an hour or so the fire has passed, the ground is black. Where once there was a tangle of shady green leaves, there is now open space and for the first time in decades, sunlight strikes the ash-covered ground.

And now in a slow and gentle rain, the seeds drift down to earth. They had hung in the branches for years but the heat has cracked them open. They have few competitors and within a week they germinate and begin to grow.

If the great trees die of old age before flames have cleared the ground for their seedlings, then they will leave no successors. Paradoxically, such a forest will not survive unless much of it is first destroyed.”

Ash as a sign of destruction – yes – but which also contains the seeds of new life. Ash Wednesday – a day that asks us to remember the destruction of sin, but in a way that allows for hope.

In a few minutes we will be invited to call to mind our sins. Our liturgy tonight leaves us to reflect on our own particular sins. Common Worship also offers a prayer listing them for us: unfaithfulness, pride, hypocrisy, self-indulgence, exploitation of others, anger, envy, intemperate love of worldly goods, dishonesty, negligence in prayer and worship…and that is just for starters…it is a long list.

For tonight – at the start of Lent –with Holy week and the cross in sight – we are asked to be especially aware of the sins common in some degree to all people. The sins, which if we are not watchful lead to Rwanda, 9/11, the Holocaust.

Tonight’s gospel suggests we should stop pointing the finger at others, like that woman caught in adultery, whose sin is obvious. It suggests that is one way of trying to evade responsibility for our own sins. Today we are asked to face the truth within ourselves – like the accusers in the gospel none of us is without sin. And if we really look properly at ourselves – it is never comfortable.

But although Ash Wednesday is about being aware of the reality of sin and evil – it also asks us to make space for hope.

Wallowing in guilt, after all, leaves us exactly where we are. Jesus doesn’t condemn the woman in the story – he tells her to change her ways. He doesn’t condemn her accusers either – he just forces them to confront their own sin – and change.

Forest fires allow new growth because they clear away dead wood and leaves. We are invited during Lent to have a go at burning away some of our sin, our self-centeredness so that God can help us to grow into the people he wants us to be.

I’m pretty good at Lent – I have a strong will – I can give up chocolate, cake – whatever. I once gave up food for a week! I can go round looking grumpy and even skinnier and colder than usual – and if I’m not careful – feel rather good about it. Which totally misses the point.

Ash Wednesday isn’t the start of a period of self-denial for it’s own sake – which makes us appreciate chocolate, alcohol, coffee even more, or which strengthens our will power.

It’s more about stripping away some of the things I rely on to make me feel good, including other people admiring my will power – to remind me that the only thing I can really rely on is Christ.

It’s about burning away some of the rubbish in my life – so that the light gets in and there is room for new growth. That shouldn’t make me grumpy – that should make me joyful. The word Lent comes from the Anglo Saxon word for spring  – the most hopeful of seasons – when new life bursts through death.

So we end our prayers of penitence with that wonderful request that God ‘forgive what we have been, help us to amend what we are, and direct what we shall be.’

It is not all about hanging our heads in shame as we acknowledge our past failures – it is a time of trying to grow as Christians.

When we receive ashes on our heads – there are those two beautiful contrasting phrases

“remember that you are dust and to dust you shall return”

reminding us that we are nothing without God.

But then “turn away from sin and be faithful to Christ” reminding us that with God, sin does not have the last word.

Ash can be a sign of destruction and sin – but it can also be the beginning of hope.