VATICAN CITY — Pope Francis urged those becoming priests to follow Christ’s example of mercy in the sacrament of confession.

“Never grow tired of being merciful. Please. You have the capacity to forgive, as did the Lord, who did not come to condemn, but to forgive! Have mercy, a lot.” he said to the 13 men being ordained to the priesthood in St. Peter’s Basilica on May 11.

“If you come to have concerns about being too much of a ‘forgiver,’ think of that saintly priest ... who went before the tabernacle and said, ‘Lord, forgive me if I have forgiven too much. But you have given me the worst example.’”

In his capacity as Bishop of Rome, Pope Francis ordained 13 men to the priesthood, 11 from the diocesan seminary in Rome and two missionaries from Pakistan and Vietnam.

Concelebrating with him were Cardinal Agostino Vallini, the vicar general of the Diocese of Rome, and Archbishop Filippo Iannone, vice general of Rome. They were joined by the auxiliary bishops of Rome, along with the rectors of the seminaries and the pastors of the newly ordained.

The Holy Father spoke to the men of his sadness at hearing of people who had the experience of being “thrashed” or “yelled at” in the confessional and never returned because they felt that “the doors of the Church were closed in their face.”

“Please, don’t do this,” he exclaimed.

Priests should follow in the way of Jesus, the Good Shepherd, who acts as the gate to the sheepfold. “The gate of mercy is the wounds of the Lord: If you don’t enter into your ministry through the wounds of Christ, you will not be good shepherds,” he cautioned.

Pope Francis also reminded those seeking ordination to be faithful to the Gospel they were taught rather than creating their own ideas.

“Teach that which you have learned in the faith; live that which you have taught. A nourishment to the people of God will, therefore, be your doctrine, which is not yours: You are not owners of doctrine! It is the doctrine of the Lord, and you must be faithful to the doctrine of the Lord.”

The Pope continued reflecting on the theme of priests as shepherds and pastors in his Sunday Angelus message, delivered soon after the Mass from the window of the apostolic palace.

Only Jesus, “the risen one, is the true Shepherd, who gives us life in abundance,” he told the crowds filling St. Peter’s Square.

On the day marked as the World Day of Prayer for Cocations, “this Sunday we pray for the shepherds of the Church,” he said. “In particular, we pray for the new priests of the diocese of Rome, who were ordained a little while ago, in St. Peter’s Basilica. A greeting for these 13 priests,” the Pope called out, as the crowds cheered and applauded.

The Holy Father then recounted an image of the priesthood told by an early Father of the Church, St. Caesarius of Arles, who explained how the “people of God must help the pastor.”

“When a calf is hungry, it goes to the cow, to the mother, to get milk,” he explained. But, often, the cow does not give milk immediately, and so the calf must knock on the mother’s udder with its nose, “and then the milk arrives.”

“It’s a beautiful image. ‘Thus you’ — says the saint — ‘must be like with the pastors [of the Church]: Always knock at their door, at their hearts, because they must give you the milk of doctrine, the milk of grace and the milk of guidance,’” Pope Francis said.

He urged the faithful to consider this image: “And I ask you, please, to pester the pastors, to bother the pastors, all of us pastors, because we must give you the milk of grace, of doctrine, of guidance.”

The Pope also noted the importance of praying for those who might be called to the priesthood or religious life, especially for the “many young people hearing the voice of the Lord, that always risks becoming stifled by other voices.”

“Maybe, here, in the square, there is someone who hears the voice of the Lord calling him to the priesthood,” he suggested. “Let us pray for him, if he is here, and for all the young people who are called.”

Pope Francis led the crowds in the Regina Coeli, and then greeted many of the pilgrim groups present.

He also invited everyone to join in a Hail Mary for mothers for Mother’s Day.