For 20 years, this Oratorian priest preached the basics of the faith to unschooled Catholics across northern France, distinguishing himself especially by serving the sick during epidemics of the plague. But in 1643 he left the French Oratory and with companions founded a new congregation of priests whose charism was the training of priests. The Congregation of Jesus and Mary, also called Eudists, was reconstituted after the French Revolution and today specializes in secondary education. John, devout from childhood, helped spread devotion to the Sacred Heart and was the first to call for an official feast day. He also organized an order of nuns to care for former prostitutes. He was canonized in 1925.