The short answer: God did. God is the author of all Scripture, and the Bible is the collection of that Scripture. Perhaps a better question is this: How were those books recognized and collected?
The collecting of the manuscripts that now make up the Holy Bible occurred as books were circulated among the people of God and recognized as Scripture. Scholars call this canonization (from “canon,” the Latin word for “measuring stick”). The Early
Church leaders did not “choose” the canon. They recognized the books that God had chosen.
Five principles guided this process. Early Church leaders considered these aspects of a given text according to the following criteria:
1. Does it have the authority of God? There may be authoritative claims about how a believer should live or what God has done. There may be an explicit claim: “Thus says the Lord.” In some form, the book will claim the authority of God.
2. Was it written by a servant of God? The author may have been a prophet or apostle, or have been sponsored by one.
3. Does it tell the truth about God? Does its content harmonize with other known Scripture? All Scripture is without error. If a book contained factual errors or contradicted other Scripture, it would fail this test.
4. Does it display the power of God? True Scripture has the power to change lives and build up the people of God.
5. Is it accepted by the people of God? The book had to be accepted by the people of God to whom it was initially given.