Some Key Terms:
Canon (Greek/ Hebrew: measuring rod)

The official list of books recognized as belonging to the Bible, and which are the standard by which all Christian teaching and practice are measured

 

The Four Gospels - Canonical Core

Matthew, Mark, Luke, and John were accepted as authoritative by 2nd century AD; undisputed and of a type and quality distinct from all other gospel titled texts.

 

Determined vs. Discerned

Church leaders observed books read liturgically by the global community of Christians, taking commonalities as a sign from the Holy Spirit that a Canon had already been received.