This is the script of this morning's Thought for the Day on BBC Radio 4's Today programme, following the terrorist attack on Ataturk Airport in Istanbul and in the light of increasing numbers of post-Brexit racist attacks in the UK:

“How long, O Lord, how long?” is the three thousand year old cry of a Hebrew poet – not an expression of misery from England football fans. It is a cry that burns in the heart and sometimes escapes the lips of those who look at the world and weep at yet another tragedy, another offence. The horror of Istanbul is just the latest in a litany of horrors. On the eve of the centenary of the slaughter at the Somme, we encounter again the sort of savagery that strips away the veneers of civilisation that we long for.

Airports are terrible targets. These are places where different worlds intersect – where diverse humanity glances off each other in transit as we circle our tiny planet. They should be places of encounter, of surprise and reconciliation – departures crisscrossing arrivals. They are places where the world connects and we are exposed to the richness of humanity and culture.

So, it is not only tragic when people-haters attack innocent travellers in the name of their violent ideologies, but it strips us of our longing for peace. “How long, O Lord, how long?” (Perhaps a question the Lord ought to be asking us.)

But, talking of stripping away the veneers of normality or civilisation, we are compelled to ask where the violence of hatred begins. The last week has seen a marked increase in racist incidents in our own country, with people being shockingly abused in public and cards being sent to Polish children telling them to get out. Maybe we are good at keeping such sentiments under the surface until they are given sanction by the erosion of the social inhibitors that normally keep them in check.

But, just as racism begins not as a screaming campaign of violence, but as a seed that gets watered by silence and by rumour, so does its antidote.

One of the stories Jesus told is pertinent here. The place where God is to be found is like a mustard seed – tiny, easy to tread on. Yet, where it takes root – hidden from sight – it has the potential to grow into a tree whose branches offer a place of refuge and habitation for the birds of the air. Of course, what is interesting about this image is that the branches don't get to be selective about which birds make their nests among them.

This is a picture not just of hospitality, but of nurture. If racism and violence grow from small seeds that are allowed to take root in the minds and hearts of our children, then it is equally true that these will be challenged not by wishful silence, but by the planting, watering and nurturing of seeds that grow hope, commitment and love.

It is not enough to dig up the bad seed; a good one has to be planted in its place.