Christian doctrine is the business of the church. The history of doctrine is not to be equated with the history of theology or the history of Christian thought. If it is, the historian runs the danger of exaggerating the significance of the idiosyncratic though of individual theologians at the expense of the common faith of the church. The private beliefs of theologians do belong to the history of doctrine, but not simply on their own terms. For on of the most decisive differences between a theologian and a philosopher is that the former understands himself as, in Origen’s classic phrase, “a man of the church,” a spokesman for the Christian community. Even in his theological speculations and in his polemic against what may have been public teaching in the church of his time, a theologian such as Origen knew himself to be accountable to the deposit of Christian revelation and the ongoing authority of the church. His personal opinions must be set into the context of the development of what the church has believed, taught, and confessed on the basis of the word of God. It is usually difficult, and sometimes impossible, to draw the line of demarcation between the teaching of the church and the theories of its teachers; what the teachers thought often reflected an earlier stage in the development or anticipated a later one.
Jaroslav Pelikan, The Emergence of the Catholic Tradition (100-600), vol. 1 in The Christian Tradition: A History of the Development of Doctrine (Chicago: University of Chicago Press, 1971), 3.