[pjr12345]

Hmm... So the roman catholic church studies for hundreds, even thousands of years, and then pronounces a doctrine.

Seems to me that everything God wanted us to know was given by the Lord to the Apostles (via the Holy Spirit), recorded by the pens of the NT writers (inspired via the Holy Spirit), and placed in the hands of the churches (preserved via the Holy Spirit). All before the last Apostle died.

Unless one of the Apostle is still living, unbeknownst to the world, I’m hard-pressed to figure out where new enlightenment will originate.

[marshmallow]

You are correct in stating that Revelation ceased with the death of the last Apostle. Yet even if Revelation is already complete, it has not been made completely explicit; it remains for Christian faith gradually to grasp its full significance over the course of the centuries. This is precisely what has happened with the Immaculate Conception and Assumption, for instance.

Lest you think that this is something novel, consider the dogma of the Holy Trinity. During the first centuries the Church sought to clarify her Trinitarian faith, both to deepen her own understanding of the faith and to defend it against the errors that were deforming it. This clarification was the work of the early councils, aided by the theological work of the Church Fathers and sustained by the Christian people's sense of the faith.

The Church is a living organism and this process did not cease with the Council of Ephesus or Nicea. It continues today.