In 1572 he became a Catholic, and soon afterwards, upon obtaining degrees in philosophy at the University of Cologne, became professor at the Gymnasium Laurentianum at Cologne. In 1575 he was ordained priest and became parish priest at Kaiserswerth. In 1583 he was made parish priest of St. Cunibert's in Cologne, where he laboured zealously by preaching and catechetical exercises, and made many conversions. In 1593 he became regent of the Laurentian gymnasium, retaining this position for twenty-two years. From 1600 to 1606 he directed the education of princes Wilhelm and Hermann of Baden, sons of Margrave Edward Fortunatus of Baden-Baden. In 1605 he became parish priest of St. Kolumba, Cologne, and from 1610 to 1612 was also rector of the university there.