He was one of the greatest priests of the Society of Jesus. He entered the Society of Saint Ignatius when he was nineteen years old, on the feast of the Immaculate Conception. His great crusade was to bring all Protestants back from the heresies into which they had fallen in the sixteenth century. He wanted to make them members again of the one true Church, outside of which they could not be saved. He wanted very much to go to foreign missions, but was not allowed to go. He loved to climb mountains and find lonely people to whom he could teach the simple and innocent truths of the Catholic Faith. He died in the middle of a cold winter in La Louvesc in southern France. Saint Rose Philippine Duchesne chose him as one of her patrons. His most devoted client was the Cure of Ars, Saint John Marie Vianney, who got encouragement to pursue his vocation to the priesthood while praying at the tomb of Saint John Francis Regis. When the Cure of Ars was dying, he declared concerning Saint John Francis Regis, “Everything good that I have done, I owe to him.” Saint John Francis Regis established confraternities in honor of the Blessed Sacrament. He spent hours every day in the confessional. He was hated by the Huguenots. He died saying, “I see Our Lord and His Mother opening Heaven for me.” Saint John Francis Regis is the patron saint of the nuns called the Religious of the Cenacle. He is also the patron saint of Kansas City, Missouri.