When Fernando Meirelles' Netflix-made The Two Popes was unveiled at the Telluride Film Festival earlier this year, it was 'an unexpected hit', according to Variety. Word had it that this story of Pope Benedict XVI, the first pontiff to resign in six hundred years, and his successor, Argentinean Cardinal Jorge Bergoglio – the future Pope Francis – was actually, well, funny. 'I felt it really needed as many jokes as possible to engage the audience, otherwise it's two men talking about religion,' explains the Brazilian-born Meirelles.

That's not to say The Two Popes is an out-and-out comedy, but the film treads lightly through the rituals of the Catholic Church, as the diametrically opposed Benedict (Anthony Hopkins) and Bergoglio (Jonathan Pryce) meet for head-to-heads. Based on Anthony McCarten's play The Pope, Meirelles' film does a fine job of humanising these two revered men. 'All the time I was trying was to make them – for myself – look like my uncle,' he says, 'like it is just two old men, two neighbours.'

Meirelles, whose past films include City of God and The Constant Gardener, came only from a casual religious background. 'I'm Catholic and I went to the church every week until I was 8, then my parents stopped going to church.' Apart from being married in a church, he has no further connections. 'But I like Pope Francis' politics. I wanted to know more about him.' Would he like the current Pope to see the film? 'I would love to. But if he sees it, he won't tell us.'

The initial script, centred more on Pope Francis, gradually widened out to embrace the outgoing hardliner Pope Benedict. Delicious details include his love of Formula 1 motor-racing ('he was a big fan of [Michael] Schumacher') and his penchant for watching Austrian police procedural Kommissar Rex, which follows the adventures of a crime-solving Alsatian. What about the scene where the two popes share a pizza? 'No, the pizza was me! I invented the pizza!'

With two Oscar-worthy performances from Hopkins and Pryce ('it could be called "The Two Welsh Popes!"' chuckles Meirelles), so far the reaction from the Catholic Church has been positive. Meirelles, who deliberately kept the child abuse scandals in the background for fear of overpowering the story, cites a theologian he recently met. 'She said, "This is a theology that I like, that I support. It's about uncertainty. I cherish my uncertainty." And that's what the film does theologically. There's no right and wrong; there are possibilities.'

The Two Popes is in cinemas from Fri 29 Nov and available on Netflix from Fri 20 Dec.