The most significant difference between Orthodox/Catholics and us is the place Scripture and the church hold. After conversing with several priests and members of those traditions, they often say that the church created the Bible. Therefore, only the church (e.g., clergy) can correctly interpret it and have authority beyond it. Our position isn’t that they created the Bible but recognized what God had inspired and held as such throughout the existence of the church and Israel.
They already recognized certain writings as Scripture (2 Peter 3:15–16). Paul quoted Luke 10:7 in 1 Timothy 5:18, thus attributing to Luke’s gospel as Scripture. Unanimity was taught so that what was taught in one church was taught in all (1 Cor 4:17; 7:17; 16:1), and New Testament writings were circulated (Col. 4:16; 1 Thess. 5:27; 1 Peter 1:1; Rev. 1:4). Even New Testament writings are cited in early Christian letters.
Didache (AD 50–60) refers to the Lord’s Prayer as it appears in Matthew. The letter 1 Clement was written near AD 95, and he alludes to the writings of Paul as Scripture and Matthew, Luke, Acts, James, and 1 Peter. In AD 110, Ignatius alludes to Matthew, Luke, and John. Polycarp in AD 110 calls Ephesians Scripture. He also references Romans, 1 Corinthians, Galatians, Philippians, 2 Thessalonians, and 1 & 2 Timothy; he quotes Matthew, Mark, and Luke. The point is that from the first century until the Bible was officially canonized, early Christians quoted from books we call Scripture as though they were divinely inspired and authoritative.
In the second century, Melito of Sardis wrote about the Hebrew Scriptures and the books regarded as divine.
Accordingly when I went to the East and reached the place where these things were preached and done, I learned accurately the books of the Old Testament, and I send them to you as written below. These are their names: Of Moses five, Genesis, Exodus, Numbers, Leviticus, Deuteronomy; Joshua the son of Nun, Judges, Ruth, four of Kingdoms, two of Chronicles, the Psalms of David, Solomon’s Proverbs or Wisdom, Ecclesiastes, Song of Songs, Job; of the Prophets: Isaiah, Jeremiah, the Twelve [minor prophets] in one book, Daniel, Ezekiel, Esdras.
Eusebius Eccl. Hist. 4.26.14
Other lists predated Melito’s (e.g., Josephus, Against Apion [AD 94]; Bryennios List [AD 100–150]).
What precipitated the New Testament was the proposal of a canon that rejected many of the already regarded books. In AD 144, Marcion listed the gospel of Luke and ten of Paul’s epistles, omitting the rest of the New and Old Testaments. A response came in AD 180 in what’s known as the Muratorian Canon. It contained twenty-two of our twenty-seven New Testament books. This was also when Melito gave his list of the Old Testament. Athanasius’ 39th Festal Letter (AD 367) has the list of New Testament books we employ.
One rebut you may encounter is that authority among clergy is apparent in the Jerusalem Council in Acts 15. Subsequent councils look to this example as to how the church makes determinations. Eastern Orthodoxy is often called the church of Councils because it is how they solve disputes and come to the census. There are four stages: 1) assembly (Acts 15:6), 2) testimony (Acts 15:7–12), 3) decision (Acts 15:13–21), and 4) adoption (Acts 15:22–29). The main difference between then and now is that the Holy Spirit inspired those men, and they even invoked the Spirit’s activity among Cornelius to arrive at their conclusion. Moreover, when they use the word “church,” they have the clergy in mind. The church doesn’t consist solely of her ministers.
A Minister's Study 