This is the script of this morning’s Thought for the Day on BBC Radio 4’s Today programme.

What does it feel like when the shape of your world changes overnight and everything you take to be normal disappears – a familiar experience in the pandemic?

I ask the question because we are now marking two connected anniversaries: the formal creation of the German Democratic Republic on 7 October 1949 … and German reunification on 3 October 1990. The GDR only existed for half a century, but, for some people, it was their lifetime … and then it was gone.

For many people in the east of Germany reunification was a takeover that valued little from the GDR and sowed seeds of resentments that are being watered today. Ostalgie is a hankering for value.

This is not new. In these times of uncertainty I’ve been re-reading one of the foundational stories of the Bible: the exodus. Moses, the reluctant liberator, led his oppressed people out of slavery in Egypt towards a life of freedom. Yet, they now found themselves not in some instant shangri-la, but in an empty desert. And gratitude did not last long.

Almost immediately the people started complaining. And moaning about the current shapelessness of their life soon led to romanticism about the past and a form of nostalgia that quickly forgot recent reality. And while this was going on, poor old Moses had to pay attention to how to shape a future in an uncertain world. Freedom from does not lead inevitably to freedom for. How to create a good society depends on more than a dislike or selective remembering of an old bad one.

Well, according to the story, a whole generation of nostalgics had to die off before the next generation could disempower nostalgia and look to creating a different future.

Which brings me back to the German question. Was the GDR a desert experience between National Socialism and Merkel’s land? Or is the current arrangement also a transitory journey towards another land – for good or ill? No society knows what will come next. The present is always transitory – we know what we are ‘post’, but we don’t know what we are ‘pre’.

Moses’ people had to unlearn the dependencies of captivity and take responsibility for their common life. This involved the hard stuff of enshrining justice and mercy in community, polity and law – protecting poor and marginalised people, ensuring that justice could not be bought and that powerful people can be held to account.

Past glories – imagined or real – do not shape a good future. Only a humble commitment to justice can do that – however often we might fall short.