But Sajid Javid, whose resignation as the UK Health Secretary started the wave of ministerial departures that brought Boris Johnson down, told the BBC’s Sophie Raworth it was Rev Isaac’s sermon that made him decide to quit.

“It might sound a bit strange, but I was listening to the sermon by this amazing man, Reverend Les Isaac – you know, he started Street Pastors,” he said.

“I was listening to him talking about the importance of integrity in public life, and just focusing on that, I made up my mind.

“I went straight back to my office and drafted the resignation letter and went to see the prime minister later in the day.”

Words have power.

And thanks to the BBC, Rev Isaac’s message of the need for humility and integrity in public life didn’t just influence a politician’s decision, but also reached millions of people on television and online.

The words of this faith leader resonated with many members of the public, who in our post-Christian society may never consider going to church but have been flooding talk shows and posting on social media crying out for politicians to show the values he called for in that sermon.

As a PR agency specialising in helping Christian charities and organisations, we at Jersey Road know that Christians are often wary of the media, concerned about being vilified and misunderstood by them.

It is true that there are plenty of journalists who don’t understand Christianity and there are some who may have had bad experiences in their interactions with Christians. It takes courage, wisdom and skill to communicate effectively with the media.

But journalists are also, in the main, driven by a sense of responsibility to hold a mirror up to society and the desire to share stories that resonate with and reflect the public mood: stories their audiences want to hear.

In a society weary of lies, prevarication and bluster, the media are looking for people to speak up for truth and to model a better response when they have done wrong.

In a society facing recession and poverty, the media are looking for people who can speak with authority about the impact on people’s lives and advocate for justice.

In a society burdened by years of crisis, the media are looking for powerful stories of hope and redemption.

Christian charities and faith groups have a lot to say on these issues – and often they have the credibility to speak into them well.

Many have been working in their communities or campaigning for years. They know the reality of the lived experience for people on the ground. They have the credibility to speak with authority and the experience to know what people care about.

And when, like Rev Isaac, they have the courage to speak into the public square, their words may go much further than they ever expected.

Charis Gibson is Director of Communications at Jersey Road PR, an agency working with Christian organisations in Australia and the UK to help raise their profile and influence. www.jerseyroadpr.com