And you, who once were alienated and enemies in your mind by wicked works, yet now He has reconciled in the body of His flesh through death, to present you holy, and blameless, and above reproach in His sight - if indeed you continue in the faith, grounded and steadfast, and are not moved away from the hope of the gospel... (Colossians 1:21-23).
What does Paul mean when he says, "if you continue in the faith"? Is this a hypothetical case - something that might happen, or might not?
The word translated "if" in our English Bibles is better translated "assuming". If you continue in the faith, it adds nothing to Christ's finished work, but it demonstrates that you are saved. It gives assurance that you will be presented holy, without blame, and above reproach before God at the Last Day. It's not a hypothetical, it's a certainty.
If you have truly been reconciled to God through Christ, you have been made a new creature. "Therefore, if anyone is in Christ, he is a new creation" -new in quality - "old things have passed away; behold, all things have become new" (2 Corinthians 5:17).
If you profess to be the recipient of Christ's saving work, but your life does not show it, you need to honestly face this question: "Am I truly saved? Do I need to come to Christ in repentance?"
Paul tells us that the person who continues in the faith is "grounded and steadfast, and...not moved away from the hope of the gospel".