Another reason the celibate priesthood is valued in the Church is because it bears witness to something greater than this world, Fr. Selin explained.
Benedict XVI once told priests that celibacy agitates the world so much because it is a sign of the kingdom to come.
"It is true that for the agnostic world, the world in which God does not enter, celibacy is a great scandal, because it shows exactly that God is considered and experienced as reality. With the eschatological dimension of celibacy, the future world of God enters into the reality of our time. And should this disappear?" Benedict XVI said in 2010.
Christ himself said that no one would be married or given in marriage in heaven, and therefore celibacy is a sign of the beatific vision (cf. Mt 22:30-32).
"Married life will pass away when we behold God face to face and all of us become part of the bridal Church," Fr. Selin said. "The celibate is more of a direct symbol of that."
Another value of celibacy is that it allows priests a greater intimacy with Christ in more fully imitating him, Fr. Selin noted.
"The priest is ordained to be Jesus for others, so he's able to dedicate his whole body and soul first of all to God himself, and from that unity with Jesus he is able to serve the Church," he said.
"We can't get that backwards," he emphasized. Often, celibacy is presented for practical reasons of money and time, which aren't sufficient reasons to maintain the tradition.
"That's not sufficient and that doesn't fill the heart of a celibate, because he first wants intimacy with God. Celibacy first is a great, profound intimacy with Christ."
A married priest's perspective: Don't change celibate priesthood
Father Douglas Grandon is one of those rare exceptions – a married Roman Catholic priest.
He was a married Episcopalian priest when he and his family decided to enter the Catholic Church 14 years ago, and received permission from Benedict XVI to become a Catholic priest.
Even though Fr. Grandon recognizes the priest shortage, he said opening the doors to the married priesthood would not solve the root issue of that shortage.
"In my opinion, the key to solving the priest shortage is more commitment to what George Weigel calls evangelical Catholicism," Fr. Grandon told CNA.
"Whether you're Protestant or Catholic, vocations come from a very strong commitment to the basic commands of Jesus to preach the Gospel and make disciples. Wherever there's this strong evangelical commitment, wherever priests are committed to deepening people's faith and making them serious disciples, you have vocations. That is really the key."
He also said that while he's "ever so grateful" that St. John Paul II allowed for exceptions to the celibate priesthood in 1980 – allowing Protestant pastor converts like himself to become priests – he also sees the value of the celibate priesthood and does not advocate getting rid of it.
"...we really do believe the celibate vocation is a wonderful thing to be treasured, and we don't want anything to undermine that special place of celibate priesthood," he said.
"Jesus was celibate, Paul was celibate, some of the 12 were celibate, so that's a special gift that God has given to the Catholic Church."
Fr. Joshua J. Whitfield is another married priest, who resides in Dallas and is a columnist for The Dallas Morning News. He recently wrote about his experience as a married priest, but also said that he would not want the Church to change its celibacy norm.
"What we need is another Pentecost. That's how the first 'shortage' was handled. The Twelve waited for the Holy Spirit, and he delivered," Fr. Whitfield told CNA in e-mail comments.
"Seeing this crisis spiritually is what is practical. And it's the only way we're going to properly solve it…. I'm simply not convinced that the economics of (married priesthood) would result in either the growth of clergy or the Church."
A glance at what the priest shortage looks like in the United States
The Archdiocese of Los Angeles is the largest diocese in the United States, clocking in at a Catholic population of 4,029,336, according to the P.J. Kenedy and Sons Official Catholic Directory.
With 1,051 diocesan and religious priests combined, the archdiocese has one priest for every 3,833 Catholics – more than double the national rate.
Despite the large Catholic population, which presents both "a great blessing and a great challenge," Fr. Samuel Ward, the archdiocese's associate director of vocations, told CNA he doesn't hope for or anticipate any major changes to the practice of priestly celibacy.
"I believe in the great value of the celibate Roman Catholic priesthood," he said.
He also sees great reason for hope. Recent upticks in the number of seminarians and young men considering the priesthood seems to be building positive momentum for vocations in future generations.
The trend is a national one as well – CARA reports that about 100 more men were ordained to the priesthood in 2016 than in 2010. Between 2005 and 2010, there was a difference of only 4.
In the Archdiocese of New York, the second largest diocese in the United States, there is a Catholic population of 2,642,740 and 1,198 diocesan and religious priests, meaning there is one priest for every 2,205 Catholics.
"I think we're probably like most every other diocese in the country, in that over the past 40-50 years, the number of ordinations have not in any way kept pace with the number of priests who are retiring or dying," said Joseph Zwilling, director of communications for the archdiocese.
It's part of the reason why they recently underwent an extensive reorganization process, which included the closing and re-consolidation of numerous parishes, many of which had found themselves without a pastor in recent years.
"Rather than wait for it to hit crisis mode we wanted to be prudent and plan for what the future would look like here in the Archdiocese of New York," Zwilling said.
Monsignor Peter Finn has been a priest in New York for 52 years, and as rector of St. Joseph's Seminary for six years in the early 2000s, he has had several years' experience forming priests. While he admits there is a shortage, he's not convinced that doing away with celibacy would solve anything.
"After 52 years of priesthood I'm not really sure it would make any big difference," he told CNA.
That's because the crisis is not unique to the vocation of the priesthood, he said. The broader issue is a lack of commitment – not just to the priesthood, but to marriage and other vocations of consecrated life.
Fr. Selin echoed those sentiments.
"It goes deeper, it goes to a deep crisis of faith, a rampant materialism, and also at times a difficulty with making choices," he said.
So if marriage won't solve the problem, what will?
Schools, seminaries, and a culture of vocations
The Archdiocese of St. Louis, on the other hand, has not experienced such a drastic shortage. When compared with other larger dioceses in the country (those with 300,000 or more Catholics), the St. Louis Archdiocese has the most priests per capita: only 959 Catholics per priests, in 2014.
John Schwob, director of pastoral planning for the archdiocese, said this could be attributed to a number of things – large and active Catholic schools, a local diocesan seminary, and archbishops who have made vocations a pastoral priority.
"...going back to the beginning of our diocese in 1826, the early bishops made repeated trips to Europe to bring back religious and secular priests and religious men and women who built up strong Catholic parishes and schools," he told CNA. "That has created momentum that has continued for nearly 200 years."
These three things also ring true for the Diocese of Lincoln, which has a smaller population and a high priest-to-Catholic ratio: one priest for every 577 Catholics, which is less than one third of the national ratio.
As in St. Louis, Lincoln's vocations director Fr. Robert Matya credits many of the diocese's vocations to Catholic schools with priests and religious sisters.
"The vast majority of our vocations come from the kids in our Catholic school system," Fr. Matya said.
"The unique thing about Lincoln is that the religion classes in all of our Catholic high schools are taught by priests or sisters, and that is not usually the case … the students just have greater exposure to priests and sisters than a kid who goes to high school somewhere else who doesn't have a priest teach them or doesn't have that interaction with a priest or a religious sister."
The diocese also has two orders of women religious – the Holy Spirit Adoration sisters (or the Pink Sisters) and discalced, cloistered Carmelites – who pray particularly for priests and vocations.
Msgr. Timothy Thorburn, vicar general of the Lincoln diocese, said that when the Carmelite sisters moved to the diocese in the late '90s, two local seminaries sprang up "almost overnight" - a diocesan minor seminary and a seminary for the Priestly Fraternity of Saint Peter.
"Wherever priests are being formed the devil is going to be at work, and cloistered religious are what we would consider the marines in the fight with the powers of darkness, they're the ones on the frontlines," Msgr. Thorburn told CNA.
"So right in the midst of the establishment of these two seminaries, the Carmelite sisters... asked if they could look at building a monastery in our diocese."
A commitment to authentic and orthodox Catholic teaching is also important for vocations, Msgr. Thorburn noted.
"I grew up in the '60s and '70s and '80s, and many in the Church thought if we just became more hip, young people would be attracted to the priesthood and religious life … and the opposite occurred. Young people were repelled by that," he said.
"They wanted to make a commitment, they wanted authentic Catholic teaching, the authentic Catholic faith, they didn't want some half-baked, watered down version of the faith; that wasn't attractive to them at all. And I'd say the same is true now. The priesthood will not become more attractive if somehow the Church says married men can be ordained."
Pope Francis' solutions: Prayer, fostering vocations, and the birth rate
Pope Francis, too, does not believe that the married priesthood is the solution to the priest shortage. Before he even mentioned the married priesthood to Die Zeit, the Pope talked about prayer.
"The first [response] – because I speak as a believer – the Lord told us to pray. Prayer, prayer is missing," he told the paper.
Rose Sullivan, director of the National Conference of Diocesan Vocation Directors, and the mother of a seminarian who is about to be ordained, agrees with the Pope.
"We would not refer to it as a 'priest shortage' or a 'vocation crisis.' We would refer to it as a prayer crisis. God has not stopped calling people to their vocation, we've stopped listening; the noise of culture has gotten in the way," she said.
"Scripture says: 'Speak Lord for your servant is listening.' So the question would be, are we listening? And I would say we could do a much better job at listening."
Another solution proposed by Pope Francis: increasing the birth rate, which has plummeted in many parts of the Church, particularly in the west.
In some European countries, once the most Catholic region of the world, the birth rate has dipped so low that governments are coming up with unique ways to incentivize child-bearing.
"If there are no young men there can be no priests," the Pope said.
The vocations of marriage and priesthood are therefore inter-related, said Fr. Ward.
"They compliment each other, and are dependent upon one another. If we don't have families, we don't have anything to do as priests, and families need priests for preaching and the sacraments."
The third solution proposed by Pope Francis was working with young people and talking to them directly about vocations.
Many priests are able to trace their vocation back to a personal invitation, often made by one priest, as well as the witness of good and holy priests that were a significant part of their lives.
"A former vocation director took an informal poll, and he asked men, 'What really got you thinking about the priesthood?' And almost all of them said 'because my pastor approached me'," Fr. Selin related.
"It was the same thing with me. When a priest lives his priesthood with great joy and fidelity, he's the most effective promoter of vocations, because a young man can see himself in him."
Msgr. Thorburn added: "There is no shortage of vocations."
"God is calling a sufficient number of men in the Western Church, who by our tradition he gives the gift of celibacy with the vocation. We just have to make a place for those seeds to fall on fertile ground."
This article was originally published on CNA April 9, 2017.