“In all these passages [1 Corinthians 6:11, 2 Thessalonians 2:13, 1 Peter 1:2, and Romans 15:16] it is of the utmost importance, in order to rightly apprehend the truth intended to be conveyed, to observe that sanctification by the Spirit is treated as the first beginnings of God’s work in the souls of men, leading to the full knowledge of justification through faith in the blood-sprinkling of Jesus Christ.” – H.A. Ironside, Holiness: the False and the True
“But we ought always to give thanks to God for you, brothers beloved by the Lord, because God chose you as the firstfruits to be saved, through sanctification by the Spirit and belief in the truth.” – 2 Thessalonians 2:13, ESV
From H. A. Ironside, “2 Thessalonians 2”, Ironside’s Notes on Selected Books (1914):
Notice that God has chosen you “to salvation through sanctification” [2 Thessalonians 2:13]. That means we were aroused to realize our lost condition and our need of a Savior by the direct work of the Holy Spirit and thus we were led to trust in the Lord Jesus Christ. Sanctification of the Spirit is the initial work of God in the soul, and then when we believe the gospel we have the assurance of salvation.
Paul told the Romans that he was a minister of God to the nations so that “the offering up of the Gentiles might be acceptable, being sanctified by the Holy Ghost” (Romans 15:16). A man may preach the Word with great liberty and power, but unless the Holy Spirit applies the Word to the hearts, illumines the minds, and troubles the consciences of his listeners, his preaching will never convert a single person.
Those of us who are saved can look back and recall how the work of the Holy Spirit began in our souls. We remember the time when we were just part and parcel of the world around us, and then there came an awakening. Perhaps at first we could not understand what was happening to us. We became unhappy and dissatisfied; we desired something we had never known before; we became conscious of our sinfulness and guilt; and we cried out in our hearts for cleansing and purity-that was the sanctification of the Holy Spirit.
There is a beautiful illustration of this sanctification in Genesis 1:1-2. We read in the first verse, “In the beginning God created the heaven and the earth.” […] “And darkness was upon the face of the deep.” The scene was one of gloom and desolation, but then “the Spirit of God moved upon the face of the waters.” The word translated “moved” is sometimes used to describe a hen brooding over her nest, so we could say that “the Spirit of God brooded upon the face of the waters.” A brooding hen, although she seems quiet and inert, is actually in constant motion. Every muscle is quivering and this generates the warmth needed to hatch the eggs. So we see the Holy Spirit moving-brooding-over the waste of waters in preparation for the reorganization of the earth in order to make it fit to be man’s dwelling place.
That same blessed Holy Spirit broods over fallen man-that is, He does His sanctifying work in the sinner’s heart-and then when the light shines in, the soul is saved. “God said, Let there be light: and there was light” (Genesis 1:3). This was the beginning of the new order. Psalms 119:130 tells us, “The entrance of thy words giveth light,” but no man sees the light until he has been wakened from his sleep by the Holy Spirit.
So as 2 Thessalonians 2:13 tells us, we are chosen “to salvation through sanctification of the Spirit and belief of the truth.” 1 Peter 1:2 says of the elect that the Spirit’s sanctification leads them into the obedience of faith, which brings them to the “sprinkling of the blood of Jesus Christ.” When we, like Israel on Passover night, take our place in faith beneath that sprinkled blood, we become absolutely secure, for Jehovah said, “When I see the blood, I will pass over you” (Exodus 12:13).
Another New Testament passage that mentions the Spirit’s sanctification is 1 Corinthians 6:9-11. There Paul listed a number of evil characters (including some so vile and unclean that I almost feel like refraining from mentioning them) and then added, “Such were some of you: but ye are washed, but ye are sanctified, but ye are justified in the name of the Lord Jesus, and by the Spirit of our God.” Some of the Corinthians had lived evil lives, but they had been washed by the application of the Word of God, sanctified by the Holy Spirit, and justified in the name of the Lord Jesus. This is the order in Scripture: The Word of God is proclaimed, heard, or read. The Spirit of God sanctifies-He convicts the sinner, bringing him to the place where he desires to be saved and is ready to receive Christ. Believing the gospel, the sinner is justified by faith.
Let me give some advice to those who seek to win souls: Do not try to rash people into confessing Christ. Do not try to make them say they are saved. Try to find out if there is any real conviction of sin. Try to find out if the Spirit of God has awakened them.
The reason a great many people make a profession of Christianity in revival meetings and soon afterward drift back into their former ways is that there has been no real work of God in their souls. They have never been sanctified by the Holy Spirit; they have never known divine conviction. First people need to be awakened to see their need of Christ; then the gospel can be given to them. That is the divine order. Sanctification by the Spirit leads to “belief of the truth.”
The full section is available online here: https://www.studylight.org/commentaries/isn/2-thessalonians-2.html