(CNN) -- Pope Benedict XVI urged a crowd of 120,000 worshippers in one of Europe's most secular countries to remain faithful to religious tradition on Sunday.
"History has demonstrated the absurdities to which man descends when he excludes God from the horizon of his choices and actions," the pope said in an open-air Mass in the Czech Republic.
"Technical developments and the improvement of social structures are important and certainly necessary, but they are not enough to guarantee the moral welfare of society," he said, according to the Vatican.
He preached Mass in Brno, the Czech Republic's second-largest city and the center of Moravia, the more religious eastern part of the country.
Worshippers came from neighboring Slovakia, Poland and Austria -- all traditionally Catholic countries -- to hear the pope, who spoke briefly in the native languages of each country before concluding in Czech. About 11,000 of the 120,000 who attended the Mass were from abroad, Martina Jandlova, the press spokeswoman of the Diocese of Brno, told CNN.
Celebrating the Mass with Benedict XVI were 40 bishops and some 1,000 priests, among them more than 200 from abroad, the Czech Bishops Conference said.
"At times one cannot help noticing, with a certain nostalgia, that the pace of modern life tends to diminish some elements of a rich heritage of faith. Yet it is important not to lose sight of the ideal expressed by traditional customs," the pope said, "and above all to maintain the spiritual patrimony inherited from your forebears, to guard it and to make it answer to the needs of the present day.
"May the Virgin Mary assist you in this, as we renew the entrustment to her of your Church and of the entire Czech nation," he added.
Benedict made reference during his homily to Sister Marie Restituta Kafkova, a Brno-born candidate for sainthood who was executed by the Nazis in 1943. As a young man growing up in Germany, the future pope was forced to join the Hitler Youth, though he came from an anti-Nazi family.
The visit was the first by a pope to Brno Diocese, which dates back to 1777, Bishop Vojtech Cikrle said in welcoming the pope to Brno.
Benedict returned to the Czech capital of Prague after the Mass for the second half of a three-day visit to the country.