The Pope’s visit to the US is testimony to one of the most unexpected transformations that has taken place in the public image of a religious leader. It goes hand in hand with the renewed importance of faith in public life in the West, in an era when predictions of its decline or even extinction have notably failed to materialise.

Benedict XVI took office three years ago with a fearsome reputation as John Paul II’s doctrinal enforcer. Liberal Roman Catholics in the West, in particular in Britain and the US, already suffering a loss of confidence because of the scandals over paedophile priests, trembled further.

As indicated by his first two encyclicals, on love and hope, Joseph Ratzinger the “rottweiler” has become “Benedict the benign”.

He has admitted that he is “deeply ashamed” of the sexual abuse scandals that have devastated the US Church in particular. Much of his time in his six days in America will be spent with cardinals and bishops, helping to restore their confidence as Christian leaders in a nation where churchgoers see themselves, as in Britain, as fighting an unending battle against the tide of secularisation.

But, beneath the Benedictine benignity, the steel remains. No one exemplifies better than the Pope the living out of the words Jesus spoke to His Apostles, recorded in Matthew’s Gospel: “Behold, I am sending you out as sheep in the midst of wolves, so be wise as serpents and innocent as doves.” The Pope’s wisdom is not in doubt.

The speeches given by the Pope and President Bush on the lawn of the White House were mirror images of each other in their mutual commitment to faith in the public space, to the importance of the trend towards globalisation.

Benedict lacks the showmanship of his predecessor, John Paul II, yet a phenomenal intelligence glows from his features like the more nuanced charisma he undoubtedly possesses. Beneath the Pope’s immaculate white attire, elegantly coiffed hair and eirenic presence rests still the tenacious man of faith who is determined beyond measure to fulfil God’s mission on His Earth in his role as successor to St Peter.

Just as Tony Blair did not officially “do God” while Prime Minister but actually did it all the time in private, the Pope will not do politics in this critical election year for the US. But merely by his presence there, he will influence the political landscape.

Methodists in Britain often tell me that they, of all the Christian denominations, are closer in spirit to Roman Catholics than any other. Hillary Clinton, a Methodist, can expect to receive a boost from the visit as she continues to win over the crucial Catholic vote. President Bush is a Methodist too. His brother Jeb, Governor of Florida, is a deeply committed Catholic convert.

So, underlying the visit is a deep, mutual commitment to faith, truth and trust. And it is in that atmosphere that the hard questions will be delivered between the two heads of state. The Pope will not pull his punches in talking on Iraq. He has vehemently opposed the war.

He is also likely to discuss Israel and the Palestinian territories, as well as US policy towards China.

He could himself be asked about the place of women in the Catholic Church, the shortage of priests and the celibacy requirement and how he will prevent paedophiles from entering seminaries in the future.