In some respects, I think it can be safely asserted that the apostle Paul’s letter to the Colossians is the other side of the coin of his letter to the Galatians. His point in Galatians is that we are justified by grace alone through faith alone in the person and work of Christ alone. This was in response to the Judaizers, who were teaching justification by faith plus observance of the Mosaic law (specifically physical circumcision). Paul argues that to seek justification by the law of Moses is to nullify grace (Gal. 2:15–21).
The issue, however, for the Colossians was not justification but spiritual empowerment for the Christian life. The spurious teaching circulating among the Colossians was that although one possessed faith in Christ for salvation, what was needed for empowerment against the forces of darkness and for subduing the desires of the flesh was a host of regulations and a rigid asceticism apart from Christ. So if the Judaizers were nullifying grace at the point of justification, the teachers that were problematic for the Colossians were nullifying grace at the point of living the Christian life. Therefore, Paul’s primary argument in Colossians is the sufficiency of Christ and the church’s completeness in Him by virtue of its union with Him by faith.
In 1:12–14, Paul says that God the Father has “qualified you to share in the inheritance of the saints in light. He has delivered us from the domain of darkness and transferred us to the kingdom of his beloved Son, in whom we have redemption, the forgiveness of sins.” He will go on to unpack the implication of these benefits later, but in verse 15 he begins a rhapsodic praise of the excellency of Him in whom we have the aforementioned benefits: “He is the image of the invisible God . . . .” I think John Calvin is correct when he writes, “Let us note that the word ‘image’ is not used of His essence, but has a reference to us. For Christ is the image of God because He makes God in a manner visible to us.”
Calvin goes on to say that “the sum is, that God in Himself, that is, in His naked majesty, is invisible; and that not only to the physical eyes, but also to human understanding; and that he is revealed to us in Christ alone, where we may behold Him as in a mirror. For in Christ He shows us His righteousness, goodness, wisdom, power, in short, His entire self. We must therefore take care not to seek Him elsewhere; for outside Christ, everything that claims to represent God will be an idol.”
In commenting on Hebrews 1:3, where the same idea is conveyed, Calvin says “that God is known truly and firmly only in Christ.” This is precisely Paul’s point to the Colossians, which is stressed with particular emphasis in 2:16–19: “Therefore let no one pass judgment on you in questions of food and drink, or with regard to a festival or a new moon or a Sabbath. These are a shadow of the things to come, but the substance belongs to Christ. Let no one disqualify you, insisting on asceticism and worship of angels, going on in detail about visions, puffed up without reason by his sensuous mind, and not holding fast to the Head, from whom the whole body, nourished and knit together through its joints and ligaments, grows with a growth that is from God.” These verses expound the implications of the fact that Jesus is “the image of the invisible God.” To seek God through elements of the ceremonial law (which were types and shadows of the coming Messiah) when the Messiah has come in the flesh is to reject the substance for the shadow. Furthermore, to seek revelations from God through personal visions or to seek the favor of angels is to undermine the uniqueness of the person of Christ, who alone is the revelation of the fullness of God.
Paul often uses the analogy of the human body to depict our union with Christ, and his reasoning here is that spiritual growth comes from God and is only through Christ. Any spiritual growth or empowerment apart from Him is superstition and “self-made religion.” Like the Colossians, the contemporary church is faced with many subtle and not-so-subtle formulas for spiritual empowerment apart from Christ. Whether it is through subjective experiences or rigid asceticism, we are bombarded with keys to unlock divine mysteries, wisdom, and power. But Paul’s contention is that the fullness of God is revealed in Christ. Spiritual growth and empowerment are the result of being built up in the knowledge of Him who is the image of the invisible God, because we are complete in Him (Col. 2:10).