Pope Francis during a Mass in Belgium’s national stadium in Brussels on Sunday gave a strong warning to Catholics about the sin of causing scandal.

He also urged the Belgian bishops to bring the evil of abuse to light and not to cover up abuse.

“Let the abuser be judged — whether a laywoman, layman, priest, or bishops, let him be judged,” the pope said during his homily on Sept. 29.

Addressing an estimated almost 40,000 people in King Baudouin Stadium in Brussels, Belgium’s largest soccer stadium, Pope Francis quoted from the Gospel of Mark: “If any of you put a stumbling block before one of these little ones who believe in me, it would be better for you if a great millstone were hung around your neck and you were thrown into the sea” (Mk 9:42).

“With these words, directed to the disciples, Jesus warns of the danger of scandal, that is, of hindering the path of the ‘little ones,’” the pope said. “It is a strong warning, a stern warning.”

The Catholic Church in Belgium is facing a significant decline in public trust. Only 50% of Belgians identified as Catholic in 2022, a drop of 16% from a decade earlier, with only 8.9% attending Mass at least once a month. Recent Vatican statistics estimate there were just over 8 million Catholics in the country at the end of 2022.

During the Mass on a cold, partly cloudy day in the small Western European country, Pope Francis also beatified Carmelite Sister Ana de Jesús, a spiritual daughter of St. Teresa of Ávila and a friend to St. John of the Cross. Born Ana de Lobera y Torres, the religious helped expand the Discalced Carmelites to France and Belgium at the turn of the 17th century.

In his homily, the pontiff praised the new blessed as one of the Church’s examples of “‘feminine styles of holiness,’ gentle but strong, made of openness, fellowship, and witness.”

“In the Church of her time, this woman was among the protagonists of a great reform movement,” he continued. “In a time marked by painful scandals, within and outside of the Christian community, she and her companions brought many people back to the faith through their simple lives of poverty, prayer, work, and charity.”

The beatification Mass was Pope Francis’ last stop at the end of nearly three days in Belgium, a constitutional monarchy, where he spoke with Catholic clergy and religious, met with approximately 300 dignitaries including King Philippe and Queen Mathilde as well as Prime Minister Alexander De Croo, and held meetings with professors and students at the country’s two Catholic universities.

The pope also had a number of off-program appointments during the visit — he surprised elderly at a care home, crashed a Catholic youth encounter, and prayed in front of the tomb of Belgian King Baudouin, a Catholic who temporarily abdicated the throne rather than sign a law legalizing abortion in 1990.

He also spent over two hours in private conversations with 17 victims of clerical sexual abuse on the evening of Sept. 27, a fact he mentioned in his homily on the sin of scandal.

“Let us listen to what Jesus says in the Gospel: Get behind me, scandalous eyes that see the needy and look away! Get behind me, scandalous hands that close your fists to hide your treasures and stash them away! Get behind me, scandalous feet that run quickly, not to draw near to those who suffer, but to avoid them and stay away!” he said. “We must leave this mentality behind! Nothing good or solid can be built upon it!”

The pope also urged Catholics to leave behind selfishness and closed-mindedness, calling them scandals that separate us from God and from our brothers and sisters in Christ.

“Selfishness, like everything that impedes charity, is ‘scandalous’ because it crushes those who are little,” he added. “It humiliates people in their dignity and suppresses the cry of the afflicted.”

At the end of Mass, Pope Francis led the tens of thousands of people in the stadium in praying the Angelus, a prayer, he said, that “should be revived, for it is a synthesis of the Christian mystery, and the Church teaches us to incorporate it into our daily activities.”

He also said that upon returning to Rome, he would accelerate the process of beatification of King Baudouin, who ruled as King of the Belgians from 1951 until his death in 1993. “May his example as a man of faith enlighten the rulers,” Francis said.

Pope Francis visited the king’s tomb in the royal crypt of the Basilica of the Sacred Heart in Brussels on Sept. 28. According to the Vatican, Pope Francis praised King Baudouin’s courage for choosing to “leave his place as king in order not to sign a murderous law” legalizing abortion.

Groups of Belgian children dressed in yellow and white for the colors of the Holy See sat on the turf in the center of the stadium, surrounding an image of a globe during the Mass. Afterward, a young girl sang a song and the Mass choir also performed other songs.

Before arriving in Belgium, Pope Francis also spent one day in Luxembourg on Sept. 26, where he met with Catholics and with local leaders, including the Catholic Grand Duke Henri and his wife, Grand Duchess María Teresa, and Prime Minister Luc Frieden.

The pontiff will return to Rome on the afternoon of Sept. 29.

This article was originally published on Catholic News Agency.