The mode of operation by which the Holy Spirit worked with the authors in order to assure an infallible and inerrant product is a matter of much speculation among theologians. The mystery remains inscrutable, but the process is intelligible and the parameters are definable.
In view of what the Bible says and shows about itself, a definition of divine inspiration can be formulated. First, the elements of a definition will be set forth; then, the definition will be derived from them. There appear to be six basic elements stated or implied in the Bible.
Biblical inspiration is not only verbal (located in the words), but it is also plenary, meaning that it extends to every part of the words and all they teach or imply. Inspiration does guarantee the truth of all the Bible teaches, implies, or entails (spiritually or factually).
Numerous passages make it evident that the locus of revelation and inspiration is the written Word, the Scriptures (Gk: grapha), not simply the idea or even the writer.
The Bible claims to be a book from God, a message with divine authority. Indeed, the biblical writers say they were moved by the Holy Spirit to utter His very words—that their message came by revelation so that what they wrote was breathed out (inspired) by God Himself.
Although substantial unanimity as to the doctrine of inspiration has prevailed among the great historical Churches of Christendom, yet there has been no little diversity of opinion among theologians and philosophical writers.
The infallibility and divine authority of the Scriptures are due to the fact that they are the word of God, and they are the word of God because they were given by the inspiration of the Holy Spirit.
If every man has the right and is bound to read the Scriptures and to judge for himself what they teach, he must have certain rules to guide him in the exercise of this privilege and duty. These rules are not arbitrary. They are not imposed by human authority.
The Bible is a plain book. It is intelligible by the people. And they have the right, and are bound to read and interpret it for themselves; so that their faith may rest on the testimony of the Scriptures, and not on that of the Church. Such is the doctrine of Protestants on this subject.