In this letter Apostle Paul clearly teaches that Jesus Christ has paid the penalty for sin, and that Christ has reconciled us to God, and that Christ gives us the pattern and the power to grow spiritually. Because Jesus is the exact likeness of God, when believers learn what he is like, we see what we need to become.
To understand the letter to the Colossians, readers need to first understand that the church was facing pressure from a cult-like heresy that promised deeper spiritual life through secret knowledge (an early form of Gnosticism). The false teachers destroyed faith in Christ by undermining Jesus Christ humanity and divinity, attempting to confuse reality from fiction and attempted to divide the physical and spiritual truth.
Paul makes it clear, that Jesus Christ alone is the source of our spiritual life, the Head of the body of believers. He is Lord of both the physical and spiritual worlds. The path to deeper spiritual life is not through religious duties, special knowledge or secrets; it is only through a clear connection with the Lord Jesus Christ.
Since Jesus Christ is Lord over all creation, we should crown him Lord over our lives. Since Jesus Christ is the Head of the body (his church), Christians should nurture our vital connection to him. Colossians allows the reader to gain a fresh appreciation of Jesus Christ as the fullness of God and the only source for living the Christian life. Believers must never let anything come between them and Jesus Christ.