Development of Doctrine
Jesus didn’t write a detailed theology manual, neither did the apostles. Instead they left a body of teaching , some of which was written down and later canonised as inspired writing.
The Church taught from this “Deposit of Faith”. As heresies arose they had to be countered and much effort of the early Church was spent on countering heresies, especially those on the nature of Christ (Adoptionism, Appolinarism, Arianism, Docetism, Nestorianism, Sabellianism and more).
In the second century two great apologists wrote extensively against heresy. St. Irenaeus write a five volume “
Against Heresies” and Justin Martyr wrote two “Apologies” and
Dialogue with Trypho (A Jew).
When the Church was no longer persecuted the bishops of the Church could get together in great councils and began to formally define many doctrines but mostly in opposition to heresy, particularly about the nature of God, and Jesus in particular.
Quotes below in are taken from the Catholic Encyclopedia.
The First Ecumenical Council (Nicea, 325)
To this council we owe The Creed (Symbolum) of Nicaea, defining against Arius the true Divinity of the Son of God (homoousios)
The Second Ecumenical Council (Constantinople I, 381)
It was directed against the followers of Macedonius, who impugned the Divinity of the Holy Ghost. To the above-mentioned Nicene Creed it added the clauses referring to the Holy Ghost (qui simul adoratur) and all that follows to the end.
The Third Ecumenical Council (Ephesus 431)
….. defined the true personal unity of Christ, declared Mary the Mother of God (theotokos) against Nestorius, Bishop of Constantinople, and renewed the condemnation of Pelagius.
The Fourth Ecumenical Council (Chalcedon (451)
…. defined the two natures (Divine and human) in Christ against Eutyches
The Fifth Ecumenical Council (Constantinople II, 553)
Condemned various writings and … confirmed the first four general councils, especially that of Chalcedon whose authority was contested by some heretics.
The Sixth Ecumenical Council (Constantinople III, 680-681)
It put an end to Monothelitism by defining two wills in Christ, the Divine and the human, as two distinct principles of operation. It anathematized Sergius, Pyrrhus, Paul, Macarius, and all their followers.
So well into the 7th century the Church was still fighting heresy about the nature of God and Christ. It is not surprising therefore that other topics such as original sin and Mary took time to develop in understanding and formal definitions.
Doctrine develops
“Is there to be no development of Doctrine in Christ’s Church? Certainly there should be great development.
Who could be so grudging towards his fellow-men and so hostile to God as to try to prevent it? But care should be taken to ensure that it is development of the faith and not alteration. Development implies that each point of doctrine is expanded within itself, while alteration suggests that a thing has been changed from what it was into something different…….
The limbs of infants are tiny, while those of young men are large, but they are the same limbs. The man has no more parts to his body than the little child…as a result it can be said that nothing new is produced in old men that was not already present in an undeveloped form when they were boys…..” (St. Vincent Lerins - died 445)
