When a liberal turns out to be an evangelical Christian, people are surprised or confused. If you are one of those who are surprised and confused, then you are a victim. A victim of liberalism’s comprehensive triumph – where the main loser has been … liberalism.

British liberalism is founded in the battle for religious liberty. The nonconformist, evangelical Christian groups that were persecuted by a society that favoured adherence only to the established church built a liberal movement that championed much wider liberty, for women, for other religious minorities, nonreligious minorities, for cultural and regional minorities, for the poor and vulnerable.

So many who declare themselves to be liberals, really aren’t

Liberalism has apparently won. Even members of the Conservative and Labour parties call themselves liberals today. Let’s be honest, you can’t work in the media without being a liberal. Even most of the journalists who write for the rightwing press are in truth liberals.

Despite my best efforts, the Liberal Democrats have not won. But irrespective of my efforts, liberalism has. Yet its triumph is hollow, just as Christianity’s apparent triumph was hollow when it became the state religion of the Roman empire.

Liberalism has eaten itself because it has eaten the very world-view that gave birth to it, that made it possible, that makes it possible.

As a Christian, of course I think there are common values to all humankind. We see them in the commandments, and in one sense we don’t need to be told them because we know instinctively what is wrong and what is right – it’s one of the key proofs that God exists.

But are there common secular values that we collectively hold here in Britain? No, I don’t think so. We don’t really have shared values. There is no unifying set of British values. It’s a myth.

What is at the heart of a liberal society? It is to uphold that we have a right to offend and a duty to tolerate offence. George Orwell said: “If liberty means anything at all, it means the right to tell people what they do not want to hear.”

In discarding Christianity, we kick away the foundations of liberalism and democracy and so we cannot then be surprised when what we call liberalism stops being liberal.

My experience is that although liberalism has won, it is now behaving like the established church of the empire in the fourth and fifth centuries. It has gained ascendancy and lost itself in the process. It isn’t very liberal any more.

So many who declare themselves to be liberals really aren’t. Five minutes on social media will give you a window into a society that condemns and judges, that leaps to take offence and pounces to cause it – liberals condemning those who don’t conform as nasty and hateful, the right condemning liberals as fragile snowflakes. But Christianity rebukes both sides: don’t judge, show kindness, show gentleness, show patience – especially to those who don’t deserve it.

Five minutes in the high street, now in the run-up to Christmas, will show you a society hooked on materialism. Five minutes eavesdropping in the cafes or glancing at people’s Facebook updates will show you a society hooked on individual achievement, on the achievement of your children, a society hooked on self-worth and pride.

I am a liberal; in economic terms I am a moderate social democrat; I believe climate change is real and I want to stop it; I am a patriotic Englishman, but I am also a passionate European and internationalist; I am a Bible-believing Christian who seeks to live obediently to God and who actively supports the freedom of everyone to either accept or reject that. That sums up my values. Are we seriously saying that they are shared by the majority of British people?

People talk about shared values today – I’ve done it myself. But when they do, what they mean is: “These are my values – and I am going to act as though they are also yours, and will demonstrate contempt for you if you depart from them.”

The phrase “the liberal elite” is usually bandied about by people who aren’t liberal but who are the elite. Whereas I am a liberal, but do not feel part of the elite.

But the cultural leaders of our day have made the arrogant and fatal assumption that we have these shared liberal values, and have sought to enforce them via John Stuart Mill’s hated tyranny of opinion and the consequences are … well, Trump and Brexit to name two!

Because every tyrant feeds and inspires the resistance that threatens to overthrow them, as a result of their own arrogance. The hand-wringing elite in our politics, media, education and business are as guilty of creating the reactionary politics of populism as much as Rupert Murdoch and Paul Dacre. Why? Because they/we assumed everyone thought the same, and dismissed with ridicule and contempt any sign of eccentricity.

• This is an edited version of the Theos Annual Lecture 2017, which will be delivered on Tuesday 28 November at the Law Society

• Tim Farron, MP for Westmorland and Lonsdale, is former leader of the Liberal Democrats