VATICAN CITY (CNS) -- The Christian journey is not a pursuit of earthly success, but of obeying God's will, knowing that at the end of time one will be with God, Pope Francis said.

Before reciting the Angelus prayer Sept. 14, Pope Francis told people in St. Peter's Square -- and a group of about 50 inmates from Rome's Rebibbia prison -- that the Christian journey leads "to real freedom, freedom from selfishness and sin."

The inmates were treated to a special morning at the Vatican, touring the Vatican Gardens and museums, arriving in the Sistine Chapel to listen to the pope's Angelus address. Antonio Paolucci, director of the Vatican Museums, led the tour.

One of the inmates, identified only as Carmine, told Vatican Radio, "We were welcomed so beautifully, which usually does not happen in society."

At the Vatican, he said, "we were treated like important guests. This was moving for all of us. It was something indescribable."

Pope Francis, commenting on the day's Gospel reading from St. Mark, spoke at the Angelus about what it means to pick up one's cross and follow Christ.

The disciples, he said, did not want to hear Jesus talk about having to suffer and die. And, in fact, Peter took Jesus aside and rebuked him for talking about the cross. And Jesus responded: "Get behind me, Satan. You are thinking not as God does, but as human beings do."

"He said Satan!" the pope said. "Jesus sees that in Peter, like in the other disciples and in each one of us, the temptation of the evil one fights against the grace of the Father."

Picking up one's cross -- "we all have them" -- means not seeking an easy life, but seeking always to do God's will, the pope said. "It involves putting into practice a complete refusal to accept the worldly mentality of placing the 'I' and one's own interests at the center of one's existence. This is not what Jesus wants from us."

Looking at the thousands of people in the square below the window of the Apostolic Palace, Pope Francis ad-libbed: "There are many young men and women in the square. I want to ask you, have you felt a desire to follow Jesus more closely? Think about it. Pray. And let the Lord speak to you."