The singer has made no secret of his religious beliefs. Raised by a Catholic father and a Protestant mother, he, The Edge and Larry Mullen Jr were once members of an evangelical worship group called Shalom. Bono has since distanced himself from organised religion, in favour of a more personal spiritual path ("I'm a need-to-practice-much-more Christian," he said in an interview in 2002, "I'm uncomfortable in churches"). But that didn't stop him sharing some good times with the late Pope John Paul II, who even tried on Bono's trademark shades during one meeting - this delicious photo opportunity was duly recorded by L'Osservatore Romano.

Christians are, apparently, accustomed to seeking spiritual meaning in Bono's lyrics. According to evangelical magazine Christianity Today, "for many Christians of a certain generation, combing through the lyrics of U2 songs (nearly all of them written by Bono) in search of biblical images or references to Jesus Christ and his teachings is almost a sport".

In his Osservatore Romano article, Vallini reviews a new book by an Italian music critic who has taken that sport to the extreme. In U2: The Name of Love, published in Italy last year, Andrea Morandi laboriously extracts Biblical allusions from almost every U2 lyric. "The presence of the Bible in the first few records," Vallini quotes Morandi as saying (in my own rough translation), "was already widely known. But the real discovery was that this presence remained, right up to the most recent CD."

Morandi and Vallini both make a convincing case for seeing Bono as a defender of the faith. Like much of the 1981 album October (made when the band were still practising Christians) Gloria sounds like it's about the singer's search for God: "I try, I try to speak up/But only in you I'm complete." Morandi even hears echoes of Psalm 51 in the lyric, "Oh Lord, if I had anything/anything at all/I'd give it to you". And the track Tomorrow is as much a call to faith as that primary-school favourite Kumbaya: "Open up, open up/To the lamb of God/He's coming back/Jesus come back." Then, of course, there's The Joshua Tree's I Still Haven't Found What I'm Looking for, a hymn to spiritual yearning if ever there was one.

But what of U2's more recent, less overtly religious, output? For Vallini, it's just as liturgically relevant. His claim that Magnificent, from the band's last album No Line On the Horizon, references the Bible just because its title sounds a bit like the Magnificat (the Song of Mary) feels like an extrapolation too far. But he makes a convincing case for another song on the album, Unknown Caller, being about looking for God ("Restart and reboot yourself/You're free to go/Shout for joy if you get the chance").

So what do you think - is U2's output little more than a rock version of The Book of Common Prayer? Should an atheist steer clear of listening to them for fear of religious conversion by stealth? And which other bands' lyrics carry this kind of none-too-subtle religious message?

END