Wherefore, since someone is in Christ—a new creation—the archaic things have passed away, behold all things have become new (2 Corinthians 5:17).
When God raised Christ out from the dead, He created a new man, in which Christ is the Head and the Church is His body (Ephesians 1:22–23). Christ’s work on the cross made it possible for God to create, out of both Jew and Gentile, one new man, abolishing in His flesh the law of commandments in dogma (Ephesians 2:15).
This new man, of whom we are now a part of, was created according to God in righteousness and piety of the truth (Ephesians 4:24). Righteousness refers to acting in a proper manner in all things. Piety is holiness in activity—living out our separation unto God: the lifting up of pious hands, without wrath and doubting (1 Timothy 2:8).
Since we are part of a new creation, we are to put off the former conduct of the old man—the corruption arising from the strong desires of error, which lead us into religious superstition and other works of the flesh, rather than into a true relationship with God. We have been born again in our spirit; therefore, we are to be renewed in the rational faculty of our minds, putting on the new man (Ephesians 4:23; 1 Peter 1:23; 1 Corinthians 6:17).
Clothing ourselves with the new man begins with setting our minds on the things above, where Christ is seated at the right hand of God (Colossians 3:1–2), aligning our thinking with what God says about us in Christ (Ephesians 4:23; Romans 5:2). From this frame of mind, our conduct will manifest the character of Christ—our Head—as we yield to the desires from the Holy Spirit, Who produces fruit in us (Galatians 5:22–25).
In the Christ, the archaic things have passed away. We are no longer under condemnation from Adam (Romans 8:1). Now, all things have become new. We are righteous before God in Christ (1 Corinthians 1:30). Therefore, as we clothe ourselves with the new man, we are renewed in the full experiential knowledge according to the image of the One creating him.