15 For neither is 1acircumcision anything nor uncircumcision, but a 1bnew creation is what matters.
151 The old creation is our old man in Adam (Eph. 4:22), our natural being by birth, without God's life and the divine nature. The new creation is the new man in Christ (Eph. 4:24), our being that is regenerated by the Spirit (John 3:6), having God's life and the divine nature wrought into it (John 3:36; 2 Pet. 1:4), having Christ as its constituent (Col. 3:10-11), and having become a new constitution. This refers to the nature, the inward and intrinsic organic constituent, of the church. Thus, the new creation is composed of sons; it is a corporate, divine sonship (3:26; 4:5, 7) brought forth through Christ's redemption, the Spirit's regeneration, and God's dispensing of Himself into us, and through our entering collectively as this new man into an organic union with the Triune God.
The old creation was old because it did not have God's element; the new creation is new because it has God as its element. Although we are still the old creation, we experience the reality of the new creation when we walk according to the Spirit (5:16, 25). The main issue in this book is that we are the new creation and that we should live by the new creation through an organic union with the Triune God. This new creation fulfills God's eternal purpose, which is to express Himself in His sonship.
Circumcision is an ordinance of the law; the new creation is the masterpiece of life with the divine nature. The former is of dead letters; the latter is of the living Spirit. Hence, the new creation is what matters. This book exposes the impotence of both the law and circumcision. The law cannot impart life (3:21) to regenerate us, and circumcision cannot energize us (5:6) to live a new creation. But the Son of God, who has been revealed in us (1:16), can enliven us and make us a new creation, and Christ, who lives in us (2:20), can afford us the riches of His life that we may live the new creation. The law has been replaced by Christ (2:19-20), and circumcision has been fulfilled by Christ's crucifixion (v. 14). Hence, neither circumcision nor uncircumcision is anything, but a new creation with Christ as its life is what matters. To be the new creation is the reason for and result of sowing unto the Spirit (v. 8). The keeping of the law and the practicing of circumcision are a sowing unto the flesh; they do not change the old creation. But sowing unto the Spirit makes us a new creation, which is re-created by the Spirit, transformed by the divine life, and constituted with the rich element of the processed Triune God by His mingling of Himself with us.