If God wrote the Bible, why do we give the human authors the credit?
God uses His people (believers) to carry out His tasks--not because He needs us, not because we do such a great job, but because He knows that we are blessed by being used by Him. We are to be His emissaries here on earth. It is clear that none of the writers of Scripture could have conjured up the writings without God inspiring them.
"And we heard this voice which came from heaven when we were with Him on the holy mountain. And so we have the prophetic word confirmed, which you do well to heed as a light that shines in a dark place, until the day dawns and the morning star rises in your hearts; knowing this first, that no prophecy of Scripture is of any private interpretation, for prophecy never came by the will of man, but holy men of God spoke as they were moved by the Holy Spirit" (2 Peter 1:18-21).