The Nicene and Post-Nicene Fathers of the Christian Church is a collection of writings by the Church Fathers who lived before and after the Council of Nicaea (325 CE). They contain early Christian doctrine, biblical commentary, and theology that form the foundation of the church and serve as an important source for the study of theology and church history. This collection provides important insights into the development of Christian theology and church thought in the early centuries, and serves as a primary source for the study of theology and church history.