He was the only German bishop to oppose Pope John Paul II in the matter of counseling pregnant women in conflict situations.

After his term ended in 2007, he took residence in the St. Vincenzstift, Aulhausen, a home for people with physical and mental disabilities, where he first served as priest.

Born in Lüdinghausen as the fifth child of a peasant family, Kamphaus achieved his Abitur from the Collegium Augustinianum Gaesdonck [de].

[2] Kamphaus earned a doctoral degree from the University of Münster in 1968 with the dissertation Von der Exegese zur Predigt.

Über die Problematik einer schrift­gemäßen Verkündigung der Oster-, Wunder- und Kindheitsgeschichten, on the topic of preaching about the biblical stories of Easter, miracles and the youth of Jesus.

[10] From 1999 to 2006 Kamphaus was president of the Kommission Weltkirche [de][4][12] of the German Bishops' Conference[1] which is responsible for international collaboration and the dialogue between religions.

He stressed the importance of songs for the mostly illiterate people, and he said: "Das Allerwichtigste ist, einfach da zu sein.

[6][3][4] Boris Rhein, minister-president of Hesse, commented that he shaped not only the Catholic Church, living in integrity and humanity as a model for engagement for the poor and disadvantaged, in service to the community.