A brief thought on commitment in British (English?) liberal religious and politcal circles

The Cambridge Unitarian Church taken today from Christ's Pieces
Tomorrow is the AGM of the Cambridge Unitarian Church where I am minister and at this time of year I often find myself thinking about about why, within contemporary liberal religious and political progressive circles anyway, it is so difficult to get more people to commit in some real and lasting way to this or that group, institution, party or other kind of community that has itself liberal progressive aims.

I don't intend here to lay out my own thoughts on why this might be the case but, instead, point you in the direction of a thought-provoking quote I came across today whilst reading an essay by Mark Fisher called "Smiley's Game: Tinker, Tailor, Soldier, Spy" (Ghosts Of My Life: Writings on Depression: Hauntology and Lost Futures, Zero Books, 2014, p. 72):

The irony in le Carré's fiction is that a sound basis for commitment is always either sought or mourned for its absence, and yet when genuine commitment appears (invariably in communism) it is treated as incomprehensible. Communism becomes fanaticism, not a strength but a weakness' (Tony Barley Taking Sides: The Fiction of John le Carré, Open University Press, 1996, p. 95).

As British (English) person who remains committed to an actually existent, radical, liberal free-thinking religious tradition as well as to leftist, progressive politics I'm acutely aware of this very British (English?) dynamic. Time and time again I encounter people who, although they claim desperately to be seeking commitment (or mourning its absence), when the opportunity for it actually stands before them, it suddenly becomes 'incomprehensible' and, as Barley says, an example of 'fanaticism, not a strength but a weakness.'

How on earth might we (I) help folk commit to a liberal, progressive religion and leftist politics but without them thinking that this is to engage in a fanatical act?

To that question I simply have no immediate answer but, tomorrow, in my address for the church's AGM I'll present a few associated thoughts.