Reviewing the Christmas services it strikes me once again how diverse a group us churchgoers are. In terms of class, race, nationality, gender and sexuality, it’s hard to imagine any other regular collective gathering that pulls in such a varied collection of people. My church is a black majority church in a gentrifying area. University professors sit next to the people who clean their offices. The Ethiopian, Trump-supporting evangelical sings the same hymns as the chap with his fine collection of Jeremy Corbyn badges. The Romanian homeless guy prays alongside the person who is transitioning and next to the old Etonian ex-army officer. Many of these people have very little in common except their faith. But this is enough for them to treat each other as extended family. And I am proud to serve as their priest.

This will be the last of the Loose canon series. And so I have been in reflective mood about what I have been trying to achieve. Partly, I suppose, it has been an exercise in apologetics – a modest attempt to try to persuade people who don’t do God that those of us who do are not necessarily bigots or idiots. And I have been trying to do this not to win converts but rather to make it easier for those of us who believe in social justice to recognise each other as fellow travellers, irrespective of our religious commitments or lack of them. But something else too, for if our little secular corner of the world is going to understand the 84% of the planet who have a religious commitment, and further understand why that figure is getting larger not smaller, then developing religious literacy and understanding the way religious expression functions in the life of believers has to be important.

The biggest mistake that those who don’t get religion tend to make about it is that they assume faith is something that goes on between the ears, that it is all a question of believing a list of (strange) things about how the world works. But for many, that does not feel like an accurate description of what faith feels from within. The words we use are as much markers of identity as they are descriptions of the universe. They are expressions of collective solidarity. Family stories – and I use the word story, as lawyers say, without prejudice. Belonging precedes believing. Hence the unity in diversity that characterises my own lovely little community church.

In political terms, this insistence on the need for a secure form of common identity increasingly gets disparaged as divisive, as so-called identity politics. Liberal commentators worry that by over-identifying our moral and political objectives with one particular group we fracture the political scene into a multiplicity of competing special interests – Black Lives Matter, LGBT rights etc. And worse, that from the perspective of identity politics, all political arguments inevitably begin with some version of the phrase: “Speaking as a X, I think Y” – which leads on to the idea that if you are not an X you cannot understand me, or represent me politically.

Those who seek a unifying political culture think of identity politics as a curse that sets people against each other. Those who defend identity politics believe that a so-called neutral and unifying culture is as much an expression of one particular power perspective as any other, and usually that of rich white men.

My sympathies are squarely on the side of those who defend identity politics. There wouldn’t have been a civil rights movement without identity politics. Nor the 20th-century revolution in gay rights. Those who worry, as Barack Obama did on the Today programme, about the “Balkanisation of society” are not wrong. But this problem is not created by the way we identify with others, because none of us has just one identity.

We are all hybrids of several overlapping identities. Some of my friends I call comrade. Some I call brothers or sisters in Christ. And our porosity to others is created by the many and various overlaps and extended sympathies that our several identities create. This is how we break out of our silos, as we do in my church with its highly diverse congregation. A healthy society is a crazy paving of interlocking and competing identities. This is how you get e pluribus unum, as the motto of the US has it. Out of many, one.

• Giles Fraser is a Guardian columnist