The Bible that is utilized as the rod of Iron in the Kingdom of Heaven is so powerful, that it must be hidden away from humanity to be hidden and only accessible to mankind for the thousand years of the Kingdom of heaven. The reason is that men cannot compete against God, and for the Lord to allow mankind to oppose Him he must hide his face, or his wisdom, His Bible, or at least the whole counsel of God. There could be no denominationalism for example if one had the one faith Bible available which exposed it. There would be no athiests, at least not in public, no socialists, etc. because the ways of God are as High as the heavens above the ways of men, and when men stand up against the authority of God they would rather mountains fall upon them than to have to go up against God.
Since it is time for the Kingdom of Heaven and the Lord to instruct humanity as if face to face through the rod of iron, We are allowed to understand the will of the Lord Eph. 5:17.