I prefer the protestant method of relying on the Scriptures. But who collected the Scriptures and assembled the Bible as we know it today?
And what did the Church do BEFORE the Bible was assembled?
The Old Testament was never in question for the primitive church, although the issue of the Deuterocanonical books was something of a controversy. The Septuagint (Greek Old Testament) included these books, whereas the Palestinian Hebrew text did not. However, we see Christian writers in the late 1st Century and early 2nd Century AD, such as Clement of Rome and Polycarp, citing the Epistles of Paul and Peter authoritatively. The ante-Nicene Fathers cited only the books that constitute the current New Testament (plus the Old Testament) as their sources. While the recent movie, "The Da Vinci Code" brought to public attention the existence of alternate Gospels, orthodox churchmen and theologians rejected their testimony and authority because the person of Jesus Christ and the theology presented contradicted the consistent positions found in the canon of the New Testament. Despite the statement in "The Da Vinci Code" that the New Testament Apocrypha were a matter of extreme controversy at the Council of Nicaea, the fact is that the resolution establishing the existing canon passed overwhelmingly.
The fact is that the New Testament was considered authoritative by orthodox Christians from the generation immediately following the apostles to the Council of Nicaea. Additionally, the key doctrines of the Christian faith, such as the divine and human nature of Jesus Christ, the Virgin Birth, the Resurrection, the Substitutionary Atonement, et. al., were evident in the writings of the ante-Nicene fathers. Church councils tend to confirm what had been the predominant practice "in the field". For example, the Catholic Council of Trent affirmed many doctrines and practices that were prevalent in the medieval Catholic Church, adding its imprimatur to what had been the prevalent teaching for several centuries.