The Orange Order recently reminded its members that RIP is not a suitable thing for good Protestants to say about the dead. “Rest in peace”, or requiescat in pace as it was in Latin, is a misguided bit of Roman Catholic dogma, they say, and superstitious nonsense to boot.

Protestants don’t pray for the dead because they believe that the dead are either in heaven or in hell, and prayer can’t make a blind bit of difference about that. Things are set at the time of death, and intercession is futile.

Moreover, it is impertinent to lobby the divine about his choice of eternal resting place for any particular soul. That’s why, for instance, there were no prayers for Diana, Princess of Wales, in Crathie Kirk, near Balmoral, where the royal family went to pray on the Sunday morning immediately after her death 20 years ago. Crathie Kirk is Church of Scotland Presbyterian, and more aligned with the theology of the Reformation than, say, the Church of England. Not praying for Diana, just hours after her death, was widely seen as callous at the time. But the kirk doesn’t think in the sentimental categories of modern remembrance.

The reason praying for the dead became a contentious issue was largely because of the way the medieval Catholic church had monetised its theology of purgatory. According to Roman doctrine, those who are not fast-tracked into heaven or hell (and you have to be especially good or especially wicked to be sent straight to either) spend a period of time in a sort of post-death holding pattern in which one’s earthly sins can be atoned for, thus to purify the soul in preparation for eternal paradise. It’s the theological equivalent of doing time for bad behaviour. And the Roman church turned it into a valuable income stream, offering time off your sentence for a fee. These were the famous indulgences that the church sold to finance its own extravagance. That, at least, is how Martin Luther saw it. To him the church had become one huge theological scam, and the unbiblical invention of purgatory was behind it. This is why Reformation Protestants like Orangemen are so hot on not saying prayers for the dead. It’s a 500-year-old battle about the power of the Roman Catholic church.

Of course, the cult of the dead wasn’t completely destroyed by the Reformation – Halloween is a throwback, for instance. And the current succession of centenaries surrounding the first world war reminds us of the extent to which we have reinvented the cult of the dead, and conscripted them into the cause of national identity. In this regard the Orangemen, with their celebration of the glorious sacrifice of the 36th (Ulster) Division at the battle of the Somme – frequently ignoring the sacrifice of the Irish Catholics they fought alongside – are serial offenders, conscripting the dead for modern political battles.

Nonetheless, after Martin Luther’s revolution, Christians would be less and less persuaded that they should genuflect before a mouldy saint’s fingernail or could add to their sanctity by muttering the rosary among the bones of dead ancestors. For Protestants, things are so much more simple. There are no second chances. As the words beside the clock on the front of Ian Paisley’s old Free Presbyterian church in Belfast put it so directly: “Time is short”. You don’t have long left is the message. Turn to Jesus now. It’s both a threat and a promise.

But what makes the Orange Order’s complaint so pointless is that the majority of people who say “Rest in peace” do not intend it as a prayer at all. The ideological infrastructure that made sense of phrases such as this has almost vanished. We use the words, but they are empty husks of meaning, shorn of the practices that gave them sense. RIP is now just something nice to say about a person after they have gone. Most people don’t believe in the God to whom this request is addressed. Nor do they imagine the person concerned asleep in the arms of Jesus. RIP is just a useful shorthand on Twitter. And people often don’t know what else to say. I’m an atheist, they say. Aye, replies the Orange Order, but are you a Protestant atheist or a Catholic one?