At school, I remember proudly revealing their Christian credentials to a friend who had been hitherto oblivious to lyrics such as “The real battle just begun / To claim the victory Jesus won” in the song ‘Sunday bloody Sunday’.

Of course, U2 have never adopted the label of ‘Christian band’, and if they had, it’s unlikely they would have enjoyed the success they have seen over four decades. The faith of Bono and his bandmates has often been hidden in plain sight. I imagine that, today, many people who listen to the music and attend the concerts are still oblivious to the biblical references in their songs. They turn up for the rock not the religion.

By the same token, U2 have never attempted to directly evangelise anyone at their concerts. Yet for those who have ears to hear, their shows and music have resonated with the Christian story of grace, redemption and hope.

My other great love is the author CS Lewis. I’ve often lamented that, since his passing, we’ve yet to see a

Christian writer bridge the gap between the sacred and secular in the way he did. His unforced ability to fire the popular imagination with Christian imagery in his Narnia series and other writings remains unmatched.

And then it struck me. For 40 years Bono, The Edge, Larry Mullen Jr and Adam Clayton have done exactly what CS Lewis did in his generation, except that they used the medium of music rather than literature.

In this way, U2 can claim the mantle from CS Lewis of doing public theology par excellence. Their shows are often likened to spiritual experiences by those who would rarely darken the door of a conventional church (and who else could get 20,000 people singing the words of Psalm 40 night after night?).

As we celebrate 40 years since the band formed in Larry Mullen Jr’s kitchen in 1976, the spiritual story of U2 told by Steve Stockman (p30) is a reminder that our own witness to Christ can be compelling and faithful without being forced or irritating. And we can pray that the faith journey of countless individuals continues to be impacted by a band that has never been afraid to talk about God.