God creates the new man, as Paul makes clear when he states that God formed in Himself one new man from the two, reconciling physical Israelites and Gentiles (Ephesians 2:15). Paul further commands Christians to put on the new man, which was created according to God in righteousness and true holiness (Ephesians 4:24). In his letter to the Colossians and Laodiceans, Paul reiterates this, instructing us to put on the new man who is renewed in knowledge according to the image of God who created him (Colossians 3:10). The new man, when first established in us by God, is immature and inexperienced, requiring our cooperation with God, the founder, to ensure growth and maturity. The new man matures through the renewal of the mind, a process Paul describes as being transformed by renewing the spirit of our mind (Ephesians 4:22-23). This renewal, a renovation to a different state, is our responsibility, as Paul exhorts us to transform ourselves by renewing our mind to prove the good, acceptable, and perfect will of God (Romans 12:1-2). This transformation of character occurs day by day as we become less conformed to this world through our active effort. We renew our minds by obeying God's law, which reflects His character and nature. Paul consistently describes the new man in terms of expected behavior and conduct. In Colossians 3:10, after commanding us to put on the new man, Paul instructs us to exhibit tender mercies, kindness, humbleness of mind, meekness, and longsuffering (Colossians 3:12). In Ephesians 4:24, after urging us to put on the new man, Paul provides specific instructions for Christian conduct, such as putting away lying and speaking truth with our neighbor (Ephesians 4:25). He describes this as walking in newness of life, a pervasive theme in Ephesians, where the new man walks worthy of the calling, conducting himself according to God's Word (Ephesians 4:1; Romans 6:4).

The concept of the new man is central to the Christian journey, as it embodies a transformation from the old life of sin to a renewed existence in righteousness. Every Christian is a new man, no longer bound by the old life of sin and slavish obedience to human nature, but set free from sin to become slaves of righteousness. This new man, being a new creation, is to be renewed in mind and conduct, embarking on a walk toward perfection. The renewal of the new man is deeply tied to the idea of spiritual circumcision, not of the flesh, but of the heart and mind. The new man is new because he has obeyed God's command to circumcise the foreskin of his heart, being renewed in the spirit of his mind. This renewal parallels the institution of the New Covenant, where God promises a new heart and a new spirit within, enabling the new man to walk in His ways. Paul consistently uses the metaphor of putting on clothes to describe adopting the Christian way of life. He commands us to put off the old man with his deeds and to put on the new man, likening this to choosing daily what to wear. This choice is ongoing, as we must repeatedly decide to adopt and maintain the Christian way of life, feeling so at home with the new man that we refuse to take it off for any reason. The analogy of clothing underscores that Christianity is a way of life, a daily decision to walk in newness. The creation of the new man is a collaborative effort between God and man. God initiates by creating the new man and compelling us to choose whether to adopt him, while we demonstrate this adoption through our conduct. Both God and man work together over a Christian's lifetime to develop the new man. God commands us to circumcise our hearts, yet He also promises to perform this circumcision, showing that righteous character is built through cooperative labor. We make ourselves a new heart by keeping His law and doing His commandments, preparing ourselves as living sacrifices for the promises of the New Covenant. Paul emphasizes this partnership, urging us to work out our salvation with fear and trembling, while reminding us that it is God who works in us to will and to do for His good pleasure.

God initially installs the new man within us, and it is our responsibility to nourish him. The new man is manifested in our conduct, reconciled to God and man, circumcised of heart, connected with the New Covenant, and adopting him is a matter of choice on our part. When we are baptized into Christ, as Paul states in Galatians 3:27, we put on Christ, sinking into Him, and that is when God first establishes the new man within us. Paul connects this putting on of Christ with reconciliation, emphasizing that there is neither Jew nor Greek, slave nor free, male nor female, for all are one in Christ Jesus. Similarly, in Colossians 3:9-11, Paul admonishes us to put on the new man, highlighting reconciliation where Christ is all and in all. Although we are to put on the new man, clothing ourselves with Christ's mind, it is Christ who clothes us with His Father's promise, the Holy Spirit, empowering us to overcome satan's deceptions and our reticence to change. As true Christians, we have tasted both the old and the new, rejecting the old man's walk in favor of the new man's way of life, which is better, different, and incompatible with the old ways. Preferring the new, we are in the process of making for ourselves a new heart, striving to walk steadfastly in that new way, true to the better covenant we have made.

As members of God's new creation, the unity He is building must deeply affect our thinking and actions. In the new order of things, as described in Colossians 3:10-11, distinctions such as Jew and Gentile, male and female, no longer exist for those who have put on the new man. For those oriented over-the-sun, these old pairings are no longer spiritually valid, though they persist in the physical order. The implication is that these divisions will completely dissolve when the physical melts away, at the time God creates the new heaven and the new earth. As new men, we are part of this new creation, characterized by unity, peace, and fellowship with the Father, with His Son, and with each other.