1Co 2:16 For who hath known the mind of the Lord, that he may instruct him? But we have the mind of Christ.
The apostle now asks with Isaiah the rhetorical question: “Who has known the mind of the Lord that he may instruct Him?” To ask the question is to answer it. God cannot be known through the wisdom or power of men. He is known only as He chooses to make Himself known. However, those who have the mind of Christ are able to understand the deep truths of God.
To review then, first there is revelation (vv. 9-12). This means that God revealed previously unknown truths to men by the Holy Spirit. These truths were made known supernaturally by the Spirit of God.
Secondly, there is inspiration (v. 13). In transmitting these truths to others, the apostles (and all other writers of the Bible) used the very words which the Holy Spirit taught them to use.
Finally, there is illumination (vv. 14-16). Not only must these truths be miraculously revealed and miraculously inspired, but they can only be understood by the supernatural power of the Holy Spirit. BBC