The following is an excerpt from The MacArthur New Testament Commentary on 1 Corinthians 6 .

Or do you not know that the unrighteous shall not inherit the kingdom of God? Do not be deceived; neither fornicators, nor idolaters, nor adulterers, nor effeminate, nor homosexuals, nor thieves, nor the covetous, nor drunkards, nor revilers, nor swindlers, shall inherit the kingdom of God. And such were some of you; but you were washed, but you were sanctified, but you were justified in the name of the Lord Jesus Christ, and in the Spirit of our God. (1 Corinthians 6:9–11)

And such were some of you. The Corinthian church, as churches today, had ex–fornicators, ex–adulterers, ex–thieves, and so on. Though many Christians have never been guilty of the particular sins just discussed, every Christian was sinful before he was saved. Every Christian is an ex–sinner. Christ came for the purpose of saving sinners (Matt. 9:13). That is the great truth of Christianity: no person has sinned too deeply or too long to be saved. “Where sin increased, grace abounded all the more” (Rom. 5:20). But some had ceased to be like that for a while, and were reverting to their old behavior.

Paul uses but (alla, the strongest Greek adversative particle) three times to indicate the contrast of the Christian life with the worldly life he has just been describing. But you were washed, but you were sanctified, but you were justified. It made no difference what they were before they were saved. God can save a sinner from any sin and all sin. But it makes a great deal of difference what a believer is like after salvation. He is to live a life that corresponds to his cleansing, his sanctification, and his justification. His Christian life is to be pure, holy, and righteous. The new life produces and requires a new kind of living.

Washed speaks of new life, of regeneration. Jesus “saved us, not on the basis of deeds which we have done in righteousness, but according to His mercy, by the washing of regeneration and renewing by the Holy Spirit” (Titus 3:5). Regeneration is God’s work of re–creation. “Therefore if any man is in Christ, he is a new creature; the old things passed away; behold, new things have come” (2 Cor. 5:17). “We are His workmanship, created in Christ Jesus” (Eph. 2:10). When a person is washed by Christ he is born again (John 3:3–8).

Sanctified speaks of new behavior. To be sanctified is to be made holy inwardly and to be able, in the Spirit’s power, to live a righteous life outwardly. Before a person is saved he has no holy nature and no capacity for holy living. But in Christ we are given a new nature and can live out the new kind of life. Sin’s total domination is broken and is replaced by a life of holiness. By their fleshly sinfulness the Corinthians were interrupting that divine work.

Justified speaks of new standing before God. In Christ we are clothed in His righteousness and God now sees in us His Son’s righteousness instead of our sin. Christ’s righteousness is credited to our account (Rom. 4:22–25). We are declared and made in the new nature righteous, holy, innocent, and guiltless because God is “the justifier of the one who has faith in Jesus” (Rom. 3:26).

The Corinthian believers had experienced transformation in the name of the Lord Jesus Christ, and in the Spirit of our God. God’s name represents His will, His power, and His work. Because of Jesus’ willing submission to the Father’s will, His death on the cross in our behalf, and His resurrection from the dead, He has provided our washing, our sanctification, and our justification.