 His hymns point to Chalcedonian Christology, and to a high interpretation of the sacraments.His hymns are mainly edited in Det Hellige Bryllup, (Oslo 1976) Sangverk for Den Norske kirke, (Oslo 1980), and may be found in the Norwegian 1998 Roman Catholic Hymn book as well as in other collections.Knudsen married Ragnhild Knudsen (née Iden) in 1964.