- _In Solitary Witness: The Life and Death of Franz Jagerstatter_ (1964)
- _War, Conscience, and Dissent_ (1967)
- _German Catholics and Hitler's Wars_ (1969)
- _Another Part of the War: The American Protestant Churches and the Second World War_ (1974)
- _Return to the Source: An Exploration of the History and Theology of Baptism_ (1975)
- _A Question of Trust: The Church in a Postmodern World_ (1991)
- _Living the Church: A Vision for the People of God_ (1996)