In 2010, in the book length interview "Light of the World," Pope Benedict told Peter Seewald, "If a pope clearly realizes that he is no longer physically, psychologically, and spiritually capable of handling the duties of his office, then he has a right and, under some circumstances, an obligation to resign."

It's clear by his shocking declaration Monday morning that Pope Benedict thinks he has reached that point.

When he was elected on April 19, 2005, he introduced himself to the Church as a "simple and humble worker in the Lord's vineyard," and his genuine humility before the duties of his office remains striking was on full display in his decision to resign.

While many of us have been more than satisfied at the level with which he was continuing to serve the whole Church at 85, it's clear that he believes that the ministry of the successor of St. Peter requires more and better than he thinks he is physically capable of giving. Out of love for the Church, he humbly became the first pope in 598 years to step down.

On a physical level, his conclusion is understandable. Very few octogenarians would have the stamina to fulfill the pope's daily schedule of continuous high-level meetings and speeches, not to mention grueling international travel and a liturgical schedule awaiting him during Holy Week that has been known to wipe out priests half his age in settings far smaller. If most pastors would be physically challenged to administer a busy parish in their mid-80s, how much more grueling must it be to preside over a Church of one billion people. And, in Pope Benedict, we're talking about a priest who's had two strokes, a pacemaker for 20 years, prostate problems and some form of degenerative joint disease.

All the same, even at obviously reduced physical capacity, Pope Benedict was still capable of leading the Church with incredible wisdom because of his unbelievably brilliant and totally undiminished mind. In one of several interviews I gave on Monday, the journalist asked what people would say his legacy would be in 10 years. I responded that it's more fitting to ask what his legacy will be in 500 years, because having him on the cathedra of Peter was like having another St. Leo the Great, someone whom future generations will likely deem a Doctor of the Church.

There are a few things about his decision to resign that are particularly striking to me.

The first is that it seems that it was not his decision, but the Lord's. He began his shocking statement to the cardinals by declaring, "After having repeatedly examined my conscience before God, I have come to the certainty that my strengths, due to an advanced age, are no longer suited to an adequate exercise of the Petrine ministry."

Pope Benedict has long called conscience an "organ of sensitivity" to the voice of God indicating to us what to do or avoid. While the judgments of conscience can always be erroneous, Pope Benedict has been tuning his "organ" for so long and fighting against false ideas of conscience that it is highly unlikely that he would be hearing the Lord say "go" when the Lord was in fact stressing "continue on." So his decision to resign does not seem to be the "no" of someone who wants to quit the burdens of the papacy but one more "yes" in a lifetime of faithful fiats to what the Lord has asked of him.

Next, by his decision Pope Benedict gave us perhaps his most powerful lesson about the importance of prayer. He finished his statement mentioning that he would "devotedly serve the Holy Church of God in the future through a life dedicated to prayer," carried out in a monastery on Vatican grounds.

Throughout his papacy in his catecheses on prayer over the last two years as well as in many talks to priests, seminarians, religious and faithful, he has repeatedly stated that the most important thing we do as Christians for God and others is to pray. By resigning the papacy in order to continue to serve the Church devotedly through prayer is to declare that he believes the work of prayer is even more important than the ministry of the papacy. And if prayer is even more important than the work of the successor of St. Peter, then it's hard to argue that any other ministry in the Church -- or any other human work -- is more important than prayer either. There's probably been no greater illustration of the lesson Jesus taught Martha and Mary in Bethany than this.

It was said that perhaps John Paul II's greatest teaching of all was his proclamation of the Gospel of redemptive suffering over the last years of his life. I anticipate that the primacy of prayer -- which means the primacy of God's action in us -- may become the lasting lesson of the final years God grants Pope Benedict.

The last item about his statement that stuck out to me was his reminder to all of us that the "Supreme Pastor" of the Church is Christ, not his earthly vicar. While popes may come and go, the Good Shepherd will never have an interregnum. For Pope Benedict, in his preaching, in his celebration of the sacraments, and in his bearing, he was always focused on Jesus, not on himself. At World Youth Days, for example, he intentionally took the focus off of the pope and had millions of young people drop to their knees with him in humble adoration of the Lord in the Eucharist.

And that's a key to understanding his startling resignation.

He seemed to fear that if he remained in office as his physical health gradually worsened, more of the focus would be on him and his frailties than on the Lord and the Lord's work. The mission that the Lord has entrusted to the Church is too important, he seemed to be saying, to allow that to happen. The Supreme Pastor needs simple and humble laborers in his fields, which are ripe for the harvest. As humble and simple as Pope Benedict remains, he no longer thought he could effectively carry out the work of harvesting, and so he thought it was time for someone more vigorous to take up the work, lest anything perish on the vine. And as Bishop Emeritus of Rome, Pope Benedict seems to want to vigorously support those efforts by the even more important labor that he still has the strength to do; his prayer.

And so while we remain shocked about his resignation of the papacy -- Catholics, after all, will always be better at celebrating a papal funeral than a papal retirement party -- I think it's important for us to move from grief to acceptance, and then to two other states.

The first is gratitude for all that Pope Benedict did in his eight years of service. It's clear by his resignation because of his physical infirmities -- which don't seem to the naked eye to be that much greater than what we've observed over the past several years -- that he must have been pushing himself to the limit for years out of loving service of Christ and us. And he accomplished so much. On all but five occasions in papal history, such gratitude was only able to be offered posthumously. We have a rare opportunity to thank him and to thank God for him, and doing so will make us more appreciative of our faith.

Second, it's now the time to begin praying for his successor and for the cardinals who will elect him. Whoever he is, he will have big fisherman's shoes to fill -- and as Pope Benedict has made clear, a heavy burden.

Father Landry is pastor of St. Bernadette Church in Fall River and former executive editor of The Anchor, the weekly newspaper of the Diocese of Fall River.