As the Apostle Paul closed his epistle to the church in Colossae he gave instructions for sharing it (Colossians 4:16). After the church in Colossae read the letter they were to give it to the church in Laodicea so that they might also read it. Paul then told the church in Colossae to read the letter written to the Laodiceans. That is, letters from inspired writers were to be shared. The result was a reliable transmission of God’s word.
Consider the security of this process. If each church made copies of letters it received from an inspired writer then shared them with other churches, there is no way any entity could supervise the process, edit a letter, or substitute a counterfeit. Individual congregations were doing the sharing.
This refutes the Roman Catholic claim that, "It is only by the divine authority of the Catholic Church that Christians know that the scripture is the word of God, and what books certainly belong to the Bible." (The Question Box, p. 46). The Roman Catholic church would not exist for centuries after this and could not have been part of this process. Understanding this reliable transmission of the scriptures helps us esteem God’s word highly and trust that it is from Him.