Jacob Rees-Mogg: 'It is dangerous for the Church to meddle in politics'

"Thus passes the glory of the world." These words used to be intoned at the beginning of each papal reign, to remind the new pope that although he may be a grand temporal figure, as Christ's vicar worthy of respect and the trappings of earthly success, yet his true vocation is not for this world, but for the next.

The job of the Church is to save souls by bringing people to the teaching of Christ. It has to engage the secular society to do this, but must not become absorbed by it. This is always the greatest challenge to the Church. When Christ was tempted by the devil, he was offered power over all the kingdoms of the world, if only he would bow down to Satan.

Christ refused, but the Church is endlessly tempted, especially as the numbers going to mass in the West declines, and the secular world laughs at, even mocks, its moral teaching. It is not impossible to envisage a situation when the congregations decline so much and vocations to the priesthood are so low that the pressure on the Church to accept the spiritual void of modernity becomes unstoppable.

Father Joseph Ratzinger, later Pope Benedict XVI, saw this very clearly as he showed in a 1969 radio broadcast. He predicted the difficulties the Church would face in an unbelieving world, but he had hope as well as circumspection.

Ratzinger forecast that the Church, "will become small and will have to start afresh, more or less from the beginning... But in all of the changes at which one might guess, the Church will find her essence afresh, and with full conviction in that which was always at her centre, faith in the Triune God, in Jesus Christ, the Son of God made man".

This is how the Church differs from the secular world. A smaller and more faithful Church is not a failure. On the other hand, a nation, an organisation or company needs to be strong to succeed. Coca-Cola must outsell Pepsi, but this is not the challenge for the Church. It is the repository of God's truth, which it must protect inviolate against secular temptation.

Ratzinger called for a Church beyond the secular state, one that would be "a more spiritual Church, not presuming upon a political mandate, flirting a little with the left and with the right". He rightly saw a Church that was not interested in passing political fads, but with eternal truth.

Indeed, it is dangerous for the Church to meddle in politics; even though, over the centuries, it has done so, because in politics, it is so easy to be wrong. The Church must not be wrong, for if she is, then there is a risk of undermining the truth.

This is fundamental for if the Church were to support one economic policy over another, and that policy fails, then even the faithful will ask, if Holy Mother can err in one area, what else might she be wrong about? Creating doubt is a great sin, hence the Church must follow the wise words of Pope Benedict and keep clear of politics.

This really is the challenge for the Church. The populist and modernisers will call for her to be relevant and to appeal to the young, to reflect today's culture and mores.

As the pews in the West have emptied over the last 60 years, this becomes more tempting, but it is none the less mistaken. The Church's values are eternal, its truth is either everything, the way to salvation, or it is nothing.

As St Paul wrote: "And if Christ be not risen again, then is our preaching vain and your faith is also vain." (1 Corinthians 15:14)

There is no middle way, the truth cannot be diluted to appease the faithless; it must be presented in all its majesty and glory. If this is then rejected by the temporal authorities, then the Church must be, as it was in its earliest days, a martyr Church.

It may be that there is no place in the public square for those who believe, and the secularists may take over education and even limit free speech, as they already do outside abortion clinics in England. But the Church must not heed this nor change, nor temper its teaching.

The martyr's blood is the seed of faith, and the rigour of truth will in the end succeed. Currently, those parts of the Church that are most rigourous, including the Institute of Christ the King, where my nephew is a seminarian, are the most successful.

Their churches are full and their seminaries overflowing.

Over 2,000 years, the Church has faced many challenges, some of which recur, and it has overcome them because it is God's foundation, even if man's building. It will continue to flourish as long as it remembers how it started and sticks to the truth.