There is an outward darkness on men and an inward darkness in men.
Outward darkness is when men do not have that light by which they are enabled to see. So outward spiritual darkness is upon men when there is nothing to enlighten them about God and spiritual things (Matt 4:16; Psa 119:105; Psa. 19:1-4,8; 2 Pet 1:19; Rom 10:15, 18). It is the work of the Holy Spirit to remove this darkness by sending the light of the gospel (Acts 13:2, 4; 16:6-10; Psa. 147:19,20).
Inward darkness, on the other hand, arises from the natural depravity and corruption of the minds of men concerning spiritual things. Man’s mind is depraved and corrupted in things which are natural, civil, political, and moral, as well as in things which are spiritual, heavenly and evangelical. This depravity is often held back from having its full effects by the common grace of the Holy Spirit. So, man’s mind being darkened, he is unable to see, receive, understand or believe to the saving of his soul. Spiritual things, or the mysteries of the gospel, without the Holy Spirit first creating within the soul a new light by which they can see and receive those things, cannot bring salvation.
However brilliant the mind may be, and however brilliant the preaching and presentation of the gospel might be, yet without the Holy Spirit first creating this light in them, they cannot receive, understand and agree with the truths preached, and so will not be led to salvation (Eph 4:17, 18).
"You've been born again through the living and abiding Word of God." It is the power of the Word that produces salvation. It is the Word of God which converts the soul, Psalm 19:7 says.
When you understand that the Word is the power that converts the soul, you preach the Word. If you don't preach the Word you don't believe that no matter what you say. It is not only the source of salvation, it is the source of sanctification. Look at verses 16 and 17. "All scripture is inspired by God and profitable for doctrine, reproof, correction, training in righteousness that the man of God and everyone who follows His pattern may be perfect or complete, equipped for every good work." It is the power of the Word that saves. It is the power of the Word that sanctifies. It provides doctrine. It reproves error and sin. It sets upright and then trains in the path of righteousness.
That's the sequence. You lay a foundation of doctrine, it reproves error and sin, then you correct that. It literally means in the Greek to make someone upright who has fallen down, you pick him back up, correct their error and their iniquity and then put them in the path of righteousness, train them to live an obedient life. The Word does that. The Word makes the man of God and everybody who follows His pattern complete. It prepares them spiritually. This is what we call the sufficiency of the Scripture. It completely saves, completely sanctifies. It sanctifies and saves those at the highest level of calling, that is the preacher, the man of God, and makes it possible for him to be an example of godliness that everybody else can follow. It is sufficient to save and sanctify all."