Just over a month from now, Ramadan begins and will stimulate a powerful expression of a faith practised by more than 1.5 billion people.

There is much pleasure in Ramadan, but its principal purpose is to remind believers of the suffering of hundreds of millions, Muslim and otherwise, who never have enough to eat.

In most Muslim countries, the spirit of Ramadan extends to people of other faiths. For the month, they are encouraged to enjoy the socialising that follows sunset and to attempt the daily fast itself. Few are unimpressed by the commitment Ramadan demands. Many are forced to examine their own view of the world.

Dynamic

Islam is the most dynamic religious movement of our times. The growth in the number of Muslims, due to their tendency to have larger families, supplemented by a significant number of conversions, is only part of the explanation.

Most of the world’s leading oil and gas exporters are Muslim states and they will become inexorably richer due to high oil prices and world oil demand growth.

But there is more to Islam’s ascent than economics. It is striking a responsive chord in hearts and minds to an extent that no other faith now does.

In Europe and North America, the tide of faith is ebbing swiftly. Pope Benedict XVI, head of the Catholic Church, is struggling to match the influence wielded by his charismatic predecessor.

Islam’s leading role

Evangelical Christians’ grip on American politics has been broken. Their representative in the White House leaves office in January. There is little to separate Republican candidate John McCain in matters of faith from his Democrat opponent, Barack Obama.

The contrast between Islam’s energy and Christianity’s decline has been reflected in the inter-faith dialogue initiated last Ramadan in an open letter signed by 138 Islamic scholars.

The letter said that the Bible and the Koran agree on two key principles: love of God and love of neighbour. It is probably the most coherent statement of shared, core Christian and Muslim values.

The responses of various Christian leaders have now been published. All welcome the letter. But their tone is consistently cautious and restrained. Implicitly, Islam’s leading role is being acknowledged.

Gathering

More than one million people will gather at the Haram Sharif in Mecca in the final stages of Ramadan, marking the remarkable demonstration of Muslim faith that is the Night of Power (Lailat al-Qadr).

And at the end of the Muslim year, more than two million will gather on the Plain of Mina outside Mecca at the climax of the annual Hajj.

It is humanity’s largest annual gathering. But the numbers there are only a fraction of those who would be on that day if only they could.

Void

Islam’s rivals may mock, but they will have to frame more compelling arguments or lose the argument in the Muslim world – and not just there.

The free finance market has delivered the greatest economic setback in living memory. Family life in some richer countries seems to be in terminal decline.

A void is emerging that modern Islam is ready to fill. And it is becoming better equipped than ever before to do so.