After working as a foreign language correspondent and studying Business Administration and Economics, Horst Krüger trained in classical singing, including art song, opera, and oratorio. Between 1965 and 1986, he served for more than twenty years as a missionary in a German-speaking community in Rio Grande do Sul, the southernmost state of Brazil.

After returning to Germany, he completed both a Master's degree and a Doctorate in Theology. He has served as a lecturer in intercultural church planting with Across, Crosscultural Studies, and Horizonte Weltweit, in cooperation with the University of Wales and New Covenant International University.

Beginning in 1996, Horst Krüger maintained a close partnership with the Jerusalem School of Synoptic Research. He was the German representative of Jerusalem Perspective. In addition, he served as President of the mission organisation "Glaube Hoffnung Liebe" ("Faith, Hope, Love"; missionghl.de). He was also the editor of the mission's bimonthly magazine of the same name, which features biblical articles and missionary news since the late 1940s. Through its ministry, Glaube Hoffnung Liebe supports daycare centres for children and missionary work in southern and northern Brazil, especially in the Amazon basin, among indigenous tribes to spread the Gospel. Horst Krüger continued to travel extensively as a speaker, giving lectures in Germany and abroad on the "Jerusalem Perspective" approach to biblical studies.

Horst was author to several books. His last, Erst die Trauben, dann der Wein, describes the period of approximately 500 years between the Old and New Testaments (between Malachi and Matthew).

Horst Krüger was married to Hildegard. They lived in Aachen, Germany, and have five children, ten grandchildren and one great-grandchild.