The Bible is God's sole communication to mankind. If we didn't have the Bible, we would not know anything about God, His plan of salvation, how He developed it through the millennia, and that Jesus Christ came to the world to show what God is really like, what He did on the cross for mankind, and how people can get through the narrow gate to eternal life. Without the Bible we wouldn't even know that there is eternal life available to us.
We would end up living lives based on cause and effect with no hope after death - that death will be end of everything and nothing beyond. Religion would be based on superstition, ritual, ceremony, human sacrifices, worshiping bits of wood and stone, and other unknown gods.