During the 1920s he devoted himself to religious art: commissions for sculptures on church buildings, participation in the “Exhibition of Religious Art” at the Ernst Arnold Gallery in Dresden and in the Vatican Mission Exhibition in the Holy Year of 1925 with his large sculpture “Pope Gregory the Great”.
In that same year he organized, and took part in, the Catholic section of the Exhibition of Ecclesiastical Art during the World's Fair in Chicago.
After 1945 Berthold Müller-Oerlinghausen made important contributions to a revival of the cultural life of the communities on Lake Constance: the rebuilding of his mosaic workshop in Kressbronn in 1946, exhibitions in the Municipal Museum of Lindau, the founding in 1947 of the “Upper Swabian Secession” (renamed “Secession of Upper Swabia/Lake Constance” in 1950), the founding of the “Artists’ Society of the Town and District of Lindau” (renamed “Lindau Art Patrons’ Society” in 1956), solo exhibitions at the Wessenberghaus in Constance and elsewhere, a retrospective exhibition at the Municipal Museum of Lindau in 1963 marking his 70th birthday.
[2] Berthold Müller-Oerlinghausen died in Kressbronn in 1979, too soon to receive the planned honorary title of professor from the State of Baden-Württemberg.
A further monograph, written by Gisela Linder,[3] was published in 1983, and a catalogue raisonné by Wolfgang Henze in 1990.