I took some fiction writing classes in college and I know authors of fiction will often create full biographies of each character in their books, including where they grew up, where they went to school and where they have worked.
Some authors will even create large boards containing the biographical information of each character. Lines will show how each character interacts with others. All this information will not make its way into the book, it is meant to make sure the portrayal of each person stays true to their history and character.
The Bible, while not a book of fiction, gives us a faithful and true narrative of the biography of God. In fact the very first words of the Bible tell us more of the Lord's history and character than we can ever imagine.
"In the beginning God created. . ." (Genesis 1:1.)
This tells us that God was present before the worlds were made, that He was already there at the beginning of mankind. It tells us that He is a creative person and that He has the power, the strength and the ability to create. It tells us that He fulfills that which He desires to do.
The Scriptures go on to reveal the person, work and heart of God as revealed through the Father, the Son and the Holy Spirit.
Just as an author has more detail about each character than is revealed in his book, there is so much more to know about the Lord than is revealed within the pages of the Bible. We will spend all eternity searching out the incredible person, work and character of our Lord, and be thrilled in doing so.
"But as it is written, Eye hath no seen, nor ear heard, neither have entered into the heart of man, the things which God hath prepared for them that love Him."
(I Corinthians 2:9.)