Notice, "if indeed you continue in the faith. . ." (verse 23). There is a stipulation, a string attached—indeed, a rope! There is a condition to being presented "holy, and blameless, and irreproachable in His sight." The subject is our ultimate glorification. Remember that the Colossians were being weaned away from a threatening but very persuasive philosophy.
Paul is establishing, "Here is the truth, and it is in the gospel. Here is our authority—Christ—who has both the status and the chronological preeminence. Christ promises to present you before the Father in glory, IF you continue in the faith."
In this context, faith indicates the church's body of teachings, the doctrine, the truth. This acts as a warning that a condition is attached to fulfilling God's purpose: A Christian must remain faithful.
John W. Ritenbaugh
The Covenants, Grace and Law (Part 20)