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*Update: This story has been updated to include a response from Fr. Herb Hayek and information about ages of past popes.

Fr. Thomas Saucier was on his way to the gym when a friend asked if he had heard the news: Pope Benedict XVI had announced his resignation. 

He learned more of the details during his workout.

"I'm doing my machine, and on all the networks, that's what they're telecasting," he said. 

Like most other people, Saucier was shocked. 

Benedict announced his resignation on Monday (Feb. 11), citing age – he's 85 years old – and health as his reasons. He will officially step down on Feb. 28 and is the first pope to resign in almost 600 years.  

The last pope to resign was Gregory XII, who stepped down in 1415 during the Great Western Schism. 

Historical evidence on papal resignation is limited, but up to 10 might have done it, according to Thomas Reese, a Jesuit priest at Georgetown University. Although uncommon, it is allowed in modern times by the code of canon law of 1917.

Not surprisingly, reflection on Benedict's resignation was part of the homily during noon mass at the St. Thomas More Newman Center in Columbia. 

The reading for the day was from Genesis 1, the passage in which the Bible recounts God's creation of the world. Saucier, pastor of the Newman Center, connected the reading and the news of the pope's resignation with the common thread: time, and the start of something new.

Saucier said Benedict's decision to resign is a good lesson in "letting go," especially as the liturgical season of Lent begins. 

“It really is a great symbolic value for us today in the sense that we live in a world in which, I think, a lot of times we’re clingy," Saucier said. "And it really gives us a wonderful witness and example of letting go of some aspects of our lives and embracing something new in another aspect.”

For Benedict, letting go of his leadership role in the Roman Catholic Church means embracing a quieter life of prayer. 

Rev. Msgr. Michael Flanagan, pastor of Our Lady of Lourdes Catholic Church in Columbia, said he understands the pope's decision – he needs to have the energy to travel, and also to conduct long ceremonies. 

"I think it's very humble of him to do it," Flanagan said. "I admire him."

Of course, like most others, he was surprised. "I guess it came up out of the blue for most of us." 

Fr. Herb Hayek, pastor of Sacred Heart Catholic Church, also highlighted Benedict's humility and honesty in saying he was too old to continue.

The previous pope, John Paul II, died in office like most popes do. Hayek said that near the end, his health had declined so much that some thought he should have resigned. 

Although Benedict's decision is surprising, Hayek said it makes sense: By 85 years old, most people – if they are still living – are retired.

At 85 years old, Benedict has already outlived his recent predecessors. John Paul II died at 84. Before him, John Paul I died after a month in office at 65. Paul VI died at 80, and Blessed John XXII at 81. Pius XII was 82 when he died. Pius XI was 81, Benedict XV was 67 and St Pius X was 79.

Looking back at more than a century's worth of popes, only Leo XIII, who died in 1903, lived to be older than Benedict is now. Leo lived to be 93. 

And aside from that, the pope is the Bishop of Rome, and most bishops are required to submit their resignation at 75.  

The surprise of Benedict's decision is because "it's so new," Hayek said. 

The Archdiocese of St. Louis released a prayer-focused response to the pope's announcement. "We pray for our Holy Father and offer him our fraternal support," the statement read. Archbishop Robert Carlson was out of town, but Auxiliary Bishop Edward Rice and Msgr. Michael Witt, professor of Church history at Kenrick-Glennon Seminary, spoke at a news conference. 

"It might be setting a trend, also," Witt said. "Pope Benedict himself, in this announcement, mentioned that it's – this is a job that requires a younger, energetic man." 

President Barack Obama extended his own appreciation to the Pope. "Michelle and I warmly remember our meeting with the Holy Father in 2009, and I have appreciated our work together over these last four years," Obama said in a statement. "The Church plays a critical role in the United States and the world, and I wish the best to those who will soon gather to choose His Holiness Pope Benedict XVI’s successor."

A Vatican spokesman said a new pope could be selected by Easter. 

The next pope will be chosen by a conclave, a meeting of cardinals who are called together for the specific purpose of electing the next pope. Speculation is already swirling about who the next leader might be.  

For more reactions to the pope's resignation announcement, read the Religion News Service reaction roundup.