Wilhelm Loehe is one of the most significant nineteenth-century figures for North American church life and mission, whose influence continues into the present. Loehe is unique for joining together aspects of the Christian life often held to be antithetical: worship and mission, orthodoxy and pietism, evangelical proclamation and diakonia, and theological imagination and practical skill in administration. Already in the nineteenth century Loehe contributed a vital principle for advancing ecumenical understanding: the idea of "open questions." When the church confesses core teachings as one, there does not need to be agreement on all secondary matters in order to live together in church fellowship.