All Scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness, that the man of God may be complete, thoroughly equipped for every good work.

It is absolutely important to hold fast the great truth that the Bible is the Word of God, and therefore "God-breathed." All apostasy starts with the denial of this fact. The Scriptures are the permanent expression of the mind and will of God. It is not merely that the truth is given in them by inspiration, but they are inspired. They are the expression of His own thoughts. They are our only authority. Upon the constant use of them depends everything. Without adhering to the Scriptures and being obedient to them, we also would be swept along by the current of apostasy. They are the one thing profitable.
Note the order: Profitable for doctrine, which we get alone from the Word of God, and which is the foundation of everything. Then follows "reproof" or conviction, and that is followed by correction and instruction for righteousness. It starts with the doctrine and leads, after conviction and correction, to righteousness. And then the man of God, obedient to the Scriptures in all things, is perfect, thoroughly finished unto every good work.

Arno Gaebelein