The bible was written by multiple people, but it was authored by One God.

If you've ever read a long multiple book series by a specific author and the author dies, and another author finishes the story, you will instantly know that it is off somehow. I've had this experience with a long series that I was reading, and I was anticipating the final book to finish the series. I didn't realize that the author had died and that the book was finished by his assistant. Without knowing that the original author had died, I immediately disliked the way the book read. It was little things, but it just didn't read the same. The story was the same, but there was a subtle difference in the writing. That last book ruined the series for me. The Bible is the only book written by multiple hands, over hundreds of years span, that is obviously authored by one mind. The men were the instruments that Almighty God used to write His Word. There is not a book in history, that was written by two or more people, that will be the same. Words and phrases change with the seasons. So no two men will write the same story the same way. The Bible is the only book that never contradicts itself. You as a human being, reading bits and pieces of the Bible, may say it contradicts. But if you'll read the whole Bible, word for word, each part compliments the other. It was inspired and authored by One God.