Why Gordon Brown should have been more honest about his religious faith when he was PM
On Christmas Day, appropriately, I reached a fascinating chapter in Gordon Brown's memoirs about whether politicians should wear their religious hearts on their sleeves or keep their faith to themselves.
The former Prime Minister, a son of the manse who grew up in Kirkcaldy, Fife, could step out of his front door and walk past nine churches within a few hundred yards of each other, so it was no surprise that his religious beliefs shaped his passionate commitment to tackling poverty and inequality.
Brown's revealing book - My Life, Our Times - looks at cultural as well as political changes. He believes historians will be astounded by "the scale and speed of the collapse in religious adherence" since the 1950s. Indeed, this year's British Social Attitudes Survey put the proportion of Britons professing to have no religion at a record high of 53%.
Similarly, a YouGov survey for The Times published this month found that 65% of people believed political figures should cordon off their religious beliefs from their decision-making, with just 14% saying the opposite and 21% saying neither" or don't know".
Despite that, the most striking and surprising passage in Brown's chapter Faith in the Public Square? is his regret at not being more open about his religious views. With the public demanding authenticity from politicians, he writes: "To expect those of us with strong beliefs to leave them at the door of the House of Commons, or No 10, is to require us to bring an incomplete version of ourselves into the public arena. If the values that matter most to me are the values I speak about least, then I am, at least in part, in denial of who I really am."
The former PM suspects that he paid a price: being viewed as a technician who lacked solid convictions. Instead of defining himself, he allowed his opponents to define him. He doesn't say so, but perhaps at the time Brown feared that talking about his roots would remind English voters of his Scottishness.
And perhaps he was too influenced by Alastair Campbell's mantra that "we don't do God". Campbell's boss, Tony Blair, attended Catholic Mass, but converted to Catholicism only after leaving Downing Street.
Of course, we can't be sure voters would have warmed to Brown more if he had been an open book. Their opinions were probably shaped more by big events such as his 2007 'election that never was', his feud with Tony Blair and the New Labour project running out of steam.
Brown says that politicians must avoid preaching to the public or claiming in effect that God is on their side. Margaret Thatcher got it wrong in her 1988 'Sermon on the Mound' in Edinburgh, as she tried to justify putting individualism before society.
But he argues powerfully that choices should not be reduced to "a theocratic and unacceptable dogmatism on the one hand and a joyless and barren secularism on the other". And that a more ethical politics would allow a healthier national conversation, helping to build a more compassionate Britain.
Some voters will doubtless be puzzled that politicians tie themselves up in knots over their faith. Tim Farron was haunted by the question of whether gay sex was a sin during this year's election campaign.
When he stood down as Liberal Democrat leader afterwards, he said: "To be a political leader and to live as a committed Christian, to hold faithfully to the Bible's teaching, has felt impossible to me."
Theresa May, a vicar's daughter, appears more relaxed about religion than Brown or Farron. She has said that "faith guides me in everything I do", but she would never make a speech like Thatcher's.
Although we are a mainly secular nation, agnostics and atheists should perhaps be a little more understanding of politicians who are motivated by their religious beliefs.
Equally, people who believe should be more tolerant of those who do not.
No politician will rebuild public trust in themselves by pretending to be something they are not.