1994 Cato lecture delivered at the Assembly of the Uniting Church in Australia in Sydney on 12 July 1994. The author considers the struggles and tensions of the sixteenth century reformation when the church was reshaped and renewed and reflects on some lessons to be learned for the church today. The author is the Hazel McCord professor of historical theology at Princeton theological seminary. USA. Since 1990 she has been president of the world alliance of reformed churches.