The faith of the Catholic people is derived from the revelation of God as found in the Holy Bible. The Church lives with that word which God has entrusted to its care, reflects upon it, ponders it through the centuries, formulates it into doctrine, setting it forth in creeds, in pronouncements of the councils, of the popes,and of the bishops. The teaching function of the Church is called the magisterium, a word which simply means “teaching function.”
Church doctrine evolves and develops as the believing community encounters new ways of understanding itself and the world in which it lives. New languages are all part of new cultures which have different ways of understanding reality. The Church gains new insight into the immutable deposit of faith and seeks new expressions for the ancient faith. At the Council of Nicaea (325 CE), the Church found a way of expressing and clarifying what the unique relationship was between the Father and the Son within the Trinity and in Jesus Christ, now that the culture and the language had moved beyond the images given in the Bible to the use of abstract concepts and definitions. Semitic languages are satisfied with images; Greek and Latin favor definitions and abstractions. In fact, heresies had arisen in explaining who the Son was in relation to the Father. Arianism taught that the Son was subordinate to the Father. Using the language of Greek philosophy, the council was able to say that the Son was of the same substance [homoousios] as the Father. This concept is not in the Bible, but it is used to explain the faith that comes from the word of the Bible; the result is doctrine that is faithful both to the word of Scripture and to the prevailing cultural forms.
Similarly, the Middle Ages gave us new tools with which to speak of the Eucharist. This development in the culture brought the Church to a new awareness of the manner in which Christ is present in the Eucharist, so that at the Council of Trent, the Church could officially adopt the terminology suggested by St. Thomas Aquinas and other medieval theologians: the concept of transubstantiation, a complete change of the inner substance of the bread and wine without a change in the outer appearances. Again, doctrine made some advances.
In the 19th and 20th centuries, the Church in its nature and government needed to be re-explained. Vatican Councils I and II found new language for the ancient faith: again a renewal of doctrine.
The word doctrine simply means teaching. The teachings of the Church are its doctrine. There is nothing to fear in using this word. It is not threatening to my intelligence to assert that the Church, through its duly authorized teachers, the popes,and the bishops, has a teaching, a body of articulations that express verbally what the community believes.