God's Word is reliable enough
“All Scripture is God-breathed and is useful for teaching, rebuking, correcting and training in righteousness, so that the servant of God may be thoroughly equipped for every good work.” (NIV) 2 Timothy 3:16-17
God's word is reliable enough to furnish man for his salvation and also to reveal the power and supremacy of God. It was very prudent that God gave man the Bible as a guide!
Perhaps, if God hasn't revealed Himself through the Bible, then we cannot know His mind towards us, or who we are, or why we are here, or from whence we came, or where we are possibly going. Without an inspired revelation from God, our existence is a fathomless riddle, a dark mystery, and a frightful leap into dreadful darkness.
Man's need for certainty is also one of the reasons why God gave us His Word that produces knowledge (Matthew 22:29), teaches us faith and how to live by it (Romans 10:17), our responsibilities (Eccl. 12:13), hope (Titus 2:3), and shows us our destiny (Eccl. 12:5).
Also, the fallibility of man (Romans 3:23), requires an infallible guide (Psalm 19:7). A human bible would be as erroneous as man, which would amount to one imperfect person telling another imperfect person what to do. But if it came from God, we have the perfect instructing the imperfect. I believe that is a better arrangement. So, mankind has a Bible that is reliable and lasting.
When His word is known and believed, it nurtures the believer’s heart and comforts him, and also deals with his will and conduct.
May we stand firm and not be deceived by fallible men and their teachings to sway us away from the perfect and reliable Word of God!