Mark Rey was born in Sigmaringen, Germany, in 1577 to a devout Catholic family. From an early age, Mark showed signs of a deep faith life, spending time in daily prayer and attending daily Mass. At university, Mark studied both canon law and civil law, opting ultimately for a secular career as an attorney. He traveled across Europe representing the wealthy and tutoring young aristocrats, but soon became disgusted with the corruption evident all around him. He made the decision to represent only the poor and destitute, and so was nicknamed “the poor man's lawyer.”
Before long, Mark abandoned his legal career and followed his older brother George into religious life. He entered the Capuchin friary at Freiburg and received the religious name Fidelis, meaning faithful.
Fidelis lived a prayerful and deeply ascetical life, often fasting on bread, water and dried fruits. He demonstrated particular zeal in the proclamation of the faith, once declaring, “Woe to me if I should prove myself but a half-hearted soldier in the service of my thorn-crowned Captain!” Aside from his preaching, Fidelis strove to practice holy silence, scrupulously avoiding any hint of gossip or detraction that might affect the reputation of another.
During the course of his life, Fidelis faced two epidemics, one physical and the other spiritual. While serving as guardian of the Capuchin friary in Feldkirch, a severe epidemic broke out in the city, ravaging the population of soldiers stationed there. Fearing nothing for himself, Fidelis went immediately to care for them, tending to both their physical and spiritual needs. His labors among the sick were so inspiring that many Calvinists converted to Catholicism.
The second epidemic Fidelis faced during his life was more widespread. Still reeling from the Reformation, many Catholics had abandoned the faith in favor of new religious movements. In 1622, the newly constituted Congregation for the Propagation of the Faith established a mission to restore the faith in Switzerland. Fidelis was sent with several Capuchin friars to preach among the Calvanists. He brought with him only four items: a Bible, a prayer book, a crucifix and a copy of the Rule.
The winter of 1622 was a period of busy preaching and theological refutation for Fidelis. He preached not only from pulpits, but in public places, even confronting the Calvinists in their gathering areas. Although his preaching was often met with hostility, he brought many others back to the Church.
On April 24 of that year, after preaching at a church in the village of Seewis, Fidelis was confronted by an angry Calvanist mob and told to choose between his Catholic faith and his life. He responded: “The Catholic faith is the faith of all ages. I do not fear death.” The mob swarmed Fidelis and bludgeoned him to death. He was 45 years old. Fidelis was canonized in 1746.