ROME— Although they’ve often been portrayed as a study in contrasts, a book excerpt released Wednesday confirms Pope Francis is actually a huge fan of his predecessor Pope Benedict XVI, calling Catholic priests everywhere to look to, and to read, Benedict whenever they have doubts about their calling.

On June 29, Emeritus Pope Benedict XVI will celebrate the 65 anniversary of his priestly ordination, which will be marked the day before with a small ceremony at the Vatican’s Secretary of State, with Pope Francis heading the VIP list.

Ahead of the celebration, the Italian newspaper La Repubblica shared an excerpt from a prologue of a book collecting Benedict’s teaching on the priesthood, written by Francis.

In it, the pope praises his predecessor, calling him a “kneeling” theologian, meaning that before being a great “teacher of the faith,” the pope emeritus is a man who “embodies holiness, a man of peace, a man of God.”

It’s with this kneeling in prayer which, according to Francis, Benedict embodies the exemplary heart of the priesthood: “That deep rootedness in God, without which all the organizational capacity and all the supposed intellectual superiority, all the money and power are useless,” Francis writes.

“[Benedict] embodies that constant relationship with the Lord Jesus without which nothing is true, everything becomes routine, priests [become] salaried [employees], bishops’ bureaucrats, and the Church is not the Church of Christ, but a product of our making, a superfluous NGO,” he adds.

Talking about the first papal resignation in over 600 years, Francis called it a “lesson for the Church.”

The pope quotes one of Benedict’s last public addresses, a meditation after the weekly Sunday Angelus, on Sunday Feb. 24, 2013: “The Lord has called me to ‘scale the mountain’, to dedicate myself still more to prayer and meditation,” the retired pontiff said.

“But this does not mean abandoning the Church,” Benedict continued. “If God asks me this, it is precisely so that I might continue to serve her with the same dedication and the same love with which I have tried to give up to now, but in a way more suitable to my age and my strength.”

According to Francis, it’s from the monastery Mater Ecclesiae, a few yards from the Santa Marta residence where he lives, that Benedict delivers his “greatest lesson of ‘kneeling theology,’” because he continues to witness the “decisive factor, that inner core of priestly ministry that deacons, priests and bishops must never forget: namely, that the first and most important service isn’t the management of ‘current affairs,’ but praying for others.”

With his testimony, the pope continues, his predecessor shows that praying is not a job for a few who are particularly devout, or incapable of solving problems. Benedict, he said, shows that “doing” is not the decisive element of the priesthood, and that prayer shouldn’t be relegated to something done during one’s “free time.”

Writing specifically for other priest, Francis tells them to meditate on the pages of the book whenever they have doubts “about the center of your ministry, its meaning, its usefulness,” or about “what people really expect from us.”

Benedict’s teachings on the priesthood, the pope writes, give testimony of the job description: bringing souls closer to Christ.

The book, titled in Italian “Teaching and Learning the Love of God,” is the first volume of several that will collect the writings of the emeritus pope, both during his papacy and previous to his election as Joseph Ratzinger. Each tome will be introduced by different people, either religious or lay. It will be released in simultaneously in six different languages, including English, by Ignatius Press.

Little has been revealed by the Vatican on next week’s ceremony, beyond the fact that the guest list is limited to the heads of Vatican offices and some of Benedict’s closest collaborators.

Benedict XVI has rarely appeared in public since he stepped down from the papacy in February 2013. He’s attended the two consistories for the creation of new cardinals, held in February of 2014 and 2015. He was also present for a “Festival of Grandparents” which took place in September of 2014, and he attended the canonization Mass for popes John XXIII and John Paul II.

His addresses or remarks have been even rarer. The last time he broke his self-imposed silence was last May when, through the Vatican’s press office, he released a statement denying there’s more to the third secret of Fatima than what was revealed during John Paul II’s papacy in 2000.

Francis, however, has praised his predecessor several times, including during several of his press conferences coming back from foreign trips. On the way back both from his only African tour in Nov. 2015 and Mexico last February, Francis said Benedict launched reform both of the Vatican government and the Church’s response to clerical sexual abuse, saying he’s following the outlines in place before his pontificate.