There came a point when Fidelis became so distressed with the problems of the legal system that he left it behind and became a missionary to the protestants (especially Calvanists). A dangerous task, and he knew it.
Time came that he was giving a sermon on “One Lord, One Faith, One Baptism.” A protestant shot at him, but the bullet just missed him. After he left, he was murdered by many soldiers on his way home.
He knew what he was in for when he was sent over to head the missionaries to the protestants in Switzerland. He had quite a sense of humor and began signing many of his letters “Fidelis, who will soon be food for the worms.”
Not only did he spend his life trying to convert others to the Cathoilc faith, but he spent much time calling already-Catholics to deeper holiness: “Woe is me if I should prove myself but a half-hearted soldier in the service of my thrown-crowned Captain!”