The Catholic Church cannot "improvise" when it comes to training such priests and supporting them throughout their ministry, Pope Francis told the bishops of Italy.

"The formation we are talking about is the experience of permanent discipleship, one which draws him to Christ and helps him increasingly become like him," the pope wrote in a message to the bishops who were meeting in Assisi Nov. 10-13.

Pope Francis suggested that as the bishops review and devise ongoing formation programs for their priests, they keep in mind the many holy priests who inspired and taught them and who minister in their dioceses in parishes, schools, hospitals and among the poor.

Without attachment to things or their own self-interest, he said, such priests demonstrate how "lowering themselves and keeping nothing back is the path toward the heights which the Gospel calls love."

"Holy priests are forgiven sinners and instruments of forgiveness," the pope wrote. "Their existence speaks the language of patience and perseverance; they are not 'spiritual tourists' eternally undecided and unsatisfied because they know they are in the hands of one who always keeps his promises and whose providence ensures that nothing can ever separate them from belonging to him."

"The church does not need clerical priests whose behavior risks alienating people from the Lord, nor does it need functionary priests who, while fulfilling a role, seek their consolation far from him," the pope said.

The experience of community or at least of "priestly fraternity," he said, is essential for ensuring that a priest does not become isolated and begin thinking of himself as the "epicenter of everything."