John MacArthur wrote,
"When the Word of God is not set up as the supreme authority, division is inevitable. Such happens even in evangelical churches, when pastors and other leaders begin substituting their own ideas for the truths of Scripture. The substitution is seldom intentional, but it will always happen when the Bible is neglected. A Bible that is not studied carefully cannot be followed carefully. And where it is not followed there will be division, because there will be no common ground for beliefs and practices. When the truth of Scripture is not the sole authority, men's varied opinions become the authority."
John Wycliffe wrote on God's Word,
"The true Christian was intended by Christ to prove all things by the Word of God, all churches, all ministers, all teaching, all preaching, all doctrines, all sermons, all writings, all opinions, all practices. These are his marching orders. Prove all by the Word of God; measure all by the measure of the Bible; compare all with the standard of the Bible; weigh all in the balances of the Bible; examine all by the light of the Bible; test all in the crucible of the Bible. That which cannot abide the fire of the Bible, reject, refuse, repudiate, and cast away. This is the flag which he nailed to the mast. May it never be lowered!"