The Holy Spirit is essential to salvation, regenerating and placing believers into the body of Christ (John 3:5; 1 Cor. 12:13). He transforms the “old man” of sin into the “new man” created in righteousness (Eph. 4:22–24). Good works then flow from salvation rather than earning it (Eph. 2:8–10). The Spirit seals believers as God’s guarantee until full redemption (Eph. 1:13–14) and leads them into true spiritual maturity (Rom. 8:14).