Pope Francis said on Wednesday that bishops and priests must take care to avoid temptations in order to be an effective shepherd, protecting their flock from dangers.

He urged the Catholic faithful to pray for bishops and priests, "because if we go on the road to riches, if we go on the road to vanity, we become wolves and not shepherds."

The Pope's words came in his May 15 homily in the chapel of the Domus Sanctae Marthae residence at the Vatican.

"A bishop is not a bishop for himself," Pope Francis said. "He is for the people, and a priest is not a priest for himself. He is for the people: to serve, to nurture them, to shepherd them, who are his flock – in order to defend them from the wolves."

When the bishops and priests do this, he said, they foster a "relationship of protection and love" between God and the pastor and between the pastor and the laity.

This shows "a true love" that unites the Church, he explained.

The Pope based his homily on the Acts of the Apostles passage in which St. Paul exhorts the Church of Ephesus to guard against the "ravening wolves" and "men speaking perverse things, to draw disciples after them," Vatican Radio reports.

Pope Francis repeated his prayers for bishops and priests who face temptation.

"We are men and we are sinners," he said. "We are tempted."

He cited St. Augustine's commentaries on the prophet Ezekiel. Augustine warned against the temptations of wealth and vanity, when the bishop and priest "take from the people," make deals and become "attached to money."

The Holy Father added that "when a priest, a bishop goes after money, the people do not love him – and that's a sign….he ends badly."

A bishop or priest on "the road to vanity" is one who "enters into the spirit of careerism – and this hurts the church very much," the Pontiff said. Such a man "ends up being ridiculous: he boasts, he is pleased to be seen, all powerful – and the people do not like that!"

He pointed to the example of St. Paul, who "did not have a bank account" but worked with his hands and accomplished God's will.

Pope Francis asked the Catholic faithful to pray for bishops and priests "that we might be poor, that we might be humble, meek, in the service of the people."

He urged bishops and priests to pray much and to "boldly preach the message of salvation."