He added, using words that many disappointed Catholics had been waiting to hear: “Some members of the hierarchy didn’t own up to these painful situations and kept silence. We ask for forgiveness.”

He also acknowledged the church’s role in separating tens of thousands of unmarried mothers from their babies, and encouraged those mothers and children to reunite.

“For all those times when it was said to many single mothers who tried to look for their children who had been estranged from them, or to the children who were looking for their mothers, that it was a mortal sin: “This is not a mortal sin,” he said. “It is the Fourth Commandment! We ask for forgiveness.”

Decades of clerical abuse, forced adoptions, forced labor in industrial houses and other exploitation gutted the Catholic Church in Ireland. And as the Irish government has broken free from the church’s hold, its people have voted in ways contrary to church teaching. They have legalized divorce and same-sex marriage, and in May took a major step toward the legalization of abortion.

In a speech beside the pope on Saturday, Ireland’s prime minister, Leo Varadkar, acknowledged all of the church’s contributions to Irish society, including its hospitals and schools, but also made clear that Ireland liked the direction it was heading in.

The pope, in his homily on Sunday, seemed to have no illusions of how hard his task is.

“Let us also humbly acknowledge that, if we are honest with ourselves, we too can find the teachings of Jesus hard,” he said. “How difficult it is always to forgive those who hurt us.”