Ideologies which do not acknowledge and uphold the dignity of human life must be resisted and the Catholic Church's teaching on life affirmed, Pope Francis told a group of Catholic doctors Monday.

"The Church is for life, and her concern is that nothing is against life in the reality of a concrete existence, however weak or defenseless, even if not developed or not advanced," the pope said May 28 in the Vatican's papal hall.

He noted the "hardships and difficulties" physicians may face when they are faithful to the teachings of the Catholic Church, particularly when they promote and defend human life "from its conception to its natural end."

Doctors "are called to affirm the centrality of the patient as a person and his dignity with his inalienable rights, primarily the right to life," he said.

"The tendency to debase the sick man as a machine to be repaired, without respect for moral principles, and to exploit the weakest by discarding what does not correspond to the ideology of efficiency and profit must be resisted."

Pope Francis spoke with members of the International Federation of Associations of Catholic Physicians ahead of a congress on the theme of "Holiness of life and the medical profession, from Humanae vitae to Laudato si'" in Zagreb, Croatia May 30-June 2.

Addressing the group, he praised the fidelity of their associations to the directives of the Magisterium and encouraged them to "continue with serenity and determination on this path."

To be a Catholic doctor means to feel driven by "faith and from communion with the Church" to grow in Christian and professional formation and to know the laws of nature in order "to better serve life," he said, stressing that the participation of Catholic physicians in the life and mission of the Church is "so necessary."

Francis noted that the health and medical fields are a part of the advance of the "technocratic cultural paradigm," which adores human power without limits and makes everything irrelevant if it does not serve a person's own interests.

"Be more and more aware that today it is necessary and urgent that the action of the Catholic physician presents itself with an unmistakable clarity on the level of personal and associative testimony," he urged.

He also encouraged working together with professionals of other religious convictions who also recognize the dignity of the human person, and with priests and religious who work in the healthcare field.

Continue the journey "with joy and generosity," he said, "in collaboration with all the people and institutions that share the love of life and endeavor to serve it in its dignity and sacredness."