GLASGOW, Scotland (CNS) – Celebrating Mass for tens of thousands of faithful, Pope Benedict XVI urged Catholics to promote the “wisdom and vision” of their religion in the public square.

A society that tries to do without religion ends up living in a self-destructive moral jungle, the pope said at a liturgy in Glasgow Sept. 16, his second stop in Scotland and the first leg of a four-day trip to Great Britain.

The crowd cheered the 83-year-old pontiff when he arrived at Bellahouston Park, just after a local police bagpipe band played “Amazing Grace.” The crowd had already been warmed up by Susan Boyle, the Scottish singing sensation, who said performing at the papal Mass was the fulfillment of a lifelong dream.

The pope landed earlier in the day in Edinburgh, where he met with Queen Elizabeth II and was treated to an official state welcome. In a speech televised across the nation, the pope warned that attempts to exclude God from social and political life can lead to disaster.

He returned to that theme in Glasgow, this time exhorting Catholics not only to be examples of faith in action, but also to defend the influence of the Christian faith in the public forum. This was all the more needed at a time when the “dictatorship of relativism” threatens to distort the truth about human nature, he said.

“There are some who now seek to exclude religious belief from public discourse, to privatize it or even to paint it as a threat to equality and liberty. Yet religion is in fact a guarantee of authentic liberty and respect, leading us to look upon every person as a brother or sister,” he said.

“Society today needs clear voices which propose our right to live, not in a jungle of self-destructive and arbitrary freedoms, but in a society which works for the true welfare of its citizens and offers them guidance and protection in the face of their weakness and fragility,” he said.

In calling for the invigoration of Catholic witness in British society, the pope pointed to the example St. Ninian, who died in 432. The Scottish evangelizer’s feast fell on the day of the pope’s arrival.

St. Ninian, the pope said, was “unafraid to be a lone voice” in proclaiming the Gospel in society.

The pope had special words for young people at the Mass, telling them that firm faith could set them free from “slavery to the glittering but superficial existence” often proposed by modern culture.

“There are many temptations placed before you every day – drugs, money, sex, pornography, alcohol – which the world tells you will bring you happiness, yet these things are destructive and divisive,” he said.

“There is only one thing which lasts: the love of Jesus Christ personally for each one of you,” he said.

The pope ended his sermon by pronouncing a blessing in Scottish Gaelic, an ancient language that also was used for one of the prayers of the faithful.

The crowds welcomed the pope enthusiastically, cheering and waving large yellow and white Vatican flags and large blue and white Scottish flags.

He drove through the crowd in the popemobile before Mass, stopping to bless babies held up by security guards.

Those attending the Mass had to be in place hours before the pope arrived. Waiting for the liturgy to begin, they cheered wildly after Boyle sang “How Great Thou Art.” The crowd also was treated to songs by Michelle McManus, the 2003 winner of Britain’s “Pop Idol” and now host of a morning television program.