We are facing a crisis of trust. The latest revelations about the nursery worker in Plymouth strike at the heart of this crisis – how can we trust those entrusted with the care of our children?

The relationship of a child to an adult is the epitome of trust and this has been defiled.

People feel outraged because they have been betrayed by those they trusted with responsibility for finance, government and welfare.

What makes it worse is that those responsible do not seem to realise they have broken that trust. They think a few minimal reforms will put things right and then it's business as usual.

The result is an atmosphere of cynicism which corrodes our national life.

Trust is a precious and fragile thing. Society cannot function without it – whether it is the plumber fixing the boiler, the pilot flying our plane or the politician making our laws, we depend on it every day. But it is so quickly destroyed.

What can we do when trust is broken? It is not just about saying sorry. We get hung up on the words which, at one level, may be difficult to say, but, at another, can be too easy.

Repentance is an important word in the Christian vocabulary. It means first facing up to wrongdoing. I still think bankers and politicians are in denial. They take refuge in the defence that everyone has been doing it – it's the system.

Politicians colluded with bankers in the illusion of the financial boom. And we consumers also got carried away with it, preferring not to ask uncomfortable questions.

Then it means facing the consequences of our actions – the suffering of a generation of debt-ridden youngsters, damaging cuts in public services and deep disillusionment with our leaders. Wouldn't it be good if failed bankers met school leavers who have no jobs as a direct result of their actions?

Repentance also means making amends where possible, paying back past income gained by wrongful means, meeting face to face with people who have been hurt.

On the TV programme "The Secret Millionaire", the experience the millionaire has in working with people and organisations struggling to help those in need is usually life-changing.

Could bankers and politicians take part in something like that?

Finally repentance means accepting costly changes in attitude and behaviour to prevent actions being repeated.

Yes, systems have to change to make it harder for people to exploit them, but personal morality and strict accountability is the only sure way of rebuilding trust.

While bankers continue to accept huge, unregulated bonuses, mistrust will continue.

Trust can be rebuilt, but it can only be gradual and cannot be taken for granted.

In the case of sexual offenders, there has to be a willing acceptance of a code of behaviour with appropriate sanctions, a restricted freedom to pick up one's life again. That is also true for others who have broken trust.

Forgiveness is the other side of repentance, the possibility of a new start. But it is only possible after working through the process of repentance. There are no short-cuts.

As a nation we need some way of acknowledging what has happened to our core institutions and those who lead them and of drawing a line under it so that we can move on.

A year has passed since the financial crash and almost six months since the expenses scandal. We need honesty and humility from our leaders at last, a coming together in a common act of repentance which signifies a genuine determination to act differently.

Jews have the Day of Atonement, Christians have Ash Wednesday. Perhaps the opening of Parliament this month would be a fitting moment!