Prophetic authority
The Bible reveals clearly that God is the true source and center of authority (see Genesis 17:1; Psalm 83:18). As Creator and Lord of all nature and history, He has the right to exercise authority over humankind (see Psalm 96:2-6; Isaiah 45:22, 23).GP 74.2
In Old Testament times, God appointed certain people to serve as His prophets (see 1 Samuel 3:30; 9:9; 2 Samuel 7:2). He communicated with them through visions and dreams (see Numbers 12:6). They were God’s authoritative spokespersons to His people, just as Aaron was the authorized spokesperson for Moses (see Jeremiah 13:12; Ezekiel 24:21; Exodus 4:16). In the time of the New Testament, Jesus authorized His disciples and the New Testament prophets to proclaim His message. So Paul could say, “You received the Word of God which you heard from us . . . not as the word of men, but as it is in truth, the Word of God” (1 Thessalonians 2:13).GP 74.3
The prophetic word has authority because God gives it His authority. Moses knew that he was authorized to speak on God’s behalf. Isaiah knew it. Paul and Peter knew it (see, for instance, 2 Corinthians 10:8). And the people of God accepted them as God’s messengers.GP 74.4
In the Bible we find canonical prophets such as Moses and Jeremiah— prophets whose writings became part of the biblical canon, the books that make up the Bible. Scripture also tells us about prophets such as Nathan (see 1 Chronicles 29:29), Ahijah, and Iddo (see 2 Chronicles 9:29)—prophets whose books, though inspired, didn’t become part of the biblical canon. (They’re called “noncanonical prophets.”) We don’t know why God selected some books by inspired prophets to be in the Bible and left out others that equally inspired prophets had written. Obviously, He knew what humankind would need to understand the plan of salvation.GP 74.5
What the noncanonical prophets said or wrote was just as authoritative for the people of their time as were the books of Moses and Isaiah. For example, after David’s sin with Bathsheba, the prophet Nathan brought him a message from God. Now, the Bible of David’s time was the Torah—the first five books of the Old Testament. Nathan hadn’t written anything that was in the Bible. But not for one moment did David question Nathan’s authority. He knew that Nathan was a prophet and that Nathan’s word was authoritative for him (see 2 Samuel 12:7-14). The authority of a prophet is based on his or her inspiration; and the authority of the prophet’s writings is based on their inspiration, not on their place in the canon.GP 74.6
Since the time ofJohn the revelator, the biblical canon has been closed, and no other inspired books can be added to it. If archaeologists were to find the book of Nathan today, it wouldn’t be added to the canon but would remain an inspired book outside of the canon. And whatever theological statements it contained would remain inspired and authoritative statements, though they were outside the canon. The canon is simply the collection of books that was put together under God’s guidance as the rule of faith and practice for God’s people. The canon is the standard by which everything else has to be measured. It contains everything a person needs to know to be saved.GP 75.1
The apostle Paul wrote a number of inspired letters that were lost—for example, his letter to the Laodiceans (see Colossians 4:16) and the letter he wrote to the Corinthians before he wrote what we know as 1 Corinthians (see 1 Corinthians 5:9). If someone found these letters today, they wouldn’t become part of the Bible but would remain inspired letters outside of the canon.GP 75.2