Is the pope Catholic? Forgive the posing of a question that is usually rhetorical, the absolute benchmark of certainty, and traditionally regarded as even more settled than the one pertaining to the lavatorial arrangements of bears.

But the most alien element of doubt has been introduced to the inquiry following the pontiff's interview with a Jesuit magazine, in which he criticises his church's "obsession" with gay people, contraception and abortion, and declares that the Catholic hierarchy must dispense with power-playing. "We have to find a new balance," said Francis, "otherwise even the moral edifice of the church is likely to fall like a house of cards … The people of God want pastors, not clergy acting like bureaucrats or government officials." Well. The immediate thought is that you wouldn't want to be his life insurer at the moment. But we shall come to the form book on modern reforming popes later.

So incendiary were the interview's contents evidently deemed that it was practically smuggled out of the Vatican, with so few senior officials reportedly aware of its tenor that the consensus is that it has sent "shock waves" around the Catholic world. Its impact more than doubles down on the seismic jolt effected by the pope when he wandered back to the press seats on his plane out of Brazil a couple of months ago and addressed the issue of gay people with the words: "Who am I to judge?" That can no longer be dismissed as the sort of lunatic thing one might say having consumed an Ambien and several miniatures at 38,000ft – although one has to wonder if those hailing this latest interview as just what the church ordered have partaken of something similar down here on Earth.

After all, if we think of the Vatican as a vast and hugely successful multinational corporation, then this interview would appear to be the equivalent of a profits warning. At the very least, it would seem to be tinkering with the formula of the biggest spiritual brand in the world, analogous to Coca-Cola changing its famous recipe in 1985. I need hardly remind you how that one worked out. Familiarity is what people want in a source of comfort, be it religion or a carbonated beverage.

He is a South American, so perhaps revolutionary spirit courses through Francis's veins. But what, pray, does the Catholic church want with doubt? What does it want with humility? What does it want with that most false of modern idols, relevance? People have been claiming for centuries that the church needs to modernise to survive – reports of its brand demise being revealed as laughably premature every time. Even today, popular myth insists it is the largest landowner in the world, though more realistic estimates place it behind King Abdullah of Saudi Arabia, with our own queen in the top spot. Still, it's fair to say the Holy See isn't doing badly.

It's not broke, in any sense of the word – unless you're one of the countless unfortunates to have suffered at the hands of its edicts or its evildoers, of course – so what in his employer's name is Francis up to with this suggestion that something needs to be fixed?

The answer we are being led towards is more sensational than anything he has said so far. And given the spiritual organisation with which we are dealing here, it is obviously necessary to eliminate all other possibilities before we can accept it as the truth. But crikey, if he carries on like this, we may have to consider the almost unthinkable: that a good man has been made pope. Traditionally, such an outcome has felt beyond all realms of reason and possibility, with the notion that a decent sort of chap could politick his way to the top of Vatican's greasy poll more outlandish even than the idea that such a soul could take the White House.

All of which brings us back to the nagging conspiracy theory that a good man who becomes pope has a life expectancy slightly longer than a fruit fly. The last nice reformer to occupy the office was John Paul I, a famously warm chap who immediately moved to humanise the papacy. Just as Francis has shunned the grandeur of the papal apartment in favour of a simple room, so John Paul spoke in the first person, declined to be borne aloft on the papal throne (until he was pressured into it), refused a papal coronation in favour of a more low-key investiture, and sent the clearest of signals that he was a moderniser. A smear campaign promptly cast him as borderline incapable, with one archbishop letting it be known that "They've made Peter Sellers pope." He was dead 33 days after his election, with an autopsy deemed surplus to requirements.

The Lord moves in mysterious ways – though not a thousandth as mysterious as those of his senior personnel from time to time – so there is no earthly possibility of predicting how long the window of opportunity enjoyed by Pope Francis is likely to be. He has certainly made a lively start. But the idea that comments warmed to by atheist liberals – those great irrelevances to the church – represent some sort of material change in the complex doctrinal politics of his organisation seems doctrinally naive. Is it about to get livelier? Is the pope Catholic?

Twitter: @MarinaHyde