The central message of Colossians is the absolute supremacy and sufficiency of Jesus Christ over all creation and all spiritual powers. Paul counters the false teachings by emphasizing that Christ is the complete source of all wisdom, knowledge, salvation, and holiness.  

Major themes include:

• The Preeminence of Christ: Christ is the image of the invisible God, the Creator and sustainer of all things, the head of the Church, and Lord over all rulers and authorities.

• Redemption and Reconciliation: Through Christ's death on the cross, God has reconciled humanity to Himself, defeating the powers of darkness and canceling the record of sin.

• Fullness in Christ: Believers are "complete in Him" and do not need to add human rituals, philosophies, or mystical experiences to their faith.

• New Life in Christ: Because believers have been raised with Christ, they are called to live out their new identity by putting off sinful behaviors and developing Christian virtues like compassion, kindness, and love. 

The Structure of the letter is generally divided into two main sections:

1. Doctrinal Section (Chapters 1-2): Focuses on the person and work of Christ and warnings against the false teachings.

2. Practical Section (Chapters 3-4): Provides ethical instructions for Christian living in personal, family, and social contexts, as a response to the theological truths presented earlier.