Paul tells the Colossians, “God will present you holy, unblemished, and unblameable—if you continue in the faith.” This sounds like conditional salvation, but it is not. You are one with the Lord, and what God has joined together, no man can separate. Paul is saying, “In God’s eyes you are already holy and perfect, but you won’t see it unless you believe it. You won’t walk in that truth except by faith.”
You may ask, “How can I believe I am holy when my life is such an unholy mess?”
You can believe it because your life is hidden in Christ and he is holy and unblemished. You have a need for holiness—you can’t get in without it—but the good news is that Jesus meets your need. By his one sacrifice, you have been made holy and perfect forever (Hebrews 10:10, 14).
I know this is a lot to swallow, particularly if you have been raised on a diet of mixture. If you have had old covenant notions of faithfulness drummed into you, it’s hard not to be anxious, especially when you stumble. But Paul’s letter to the Colossians, and particularly chapter 2, is a brilliant response to the fears and anxieties of the insecure believer. Let me give you an example.
One sign that you are not continuing in the faith is that you are more conscious of your lack than you are of the Lord’s supply. You may think, I’m not holy enough, righteous enough, or fruitful enough. Look at how Paul corrects this misperception:
For in Christ all the fullness of the Deity lives in bodily form, and in Christ you have been brought to fullness. (Colossians 2:9–10a)
How do you continue in the faith? By recognizing that in Christ you lack no good thing. In Christ you have received every spiritual blessing there is. “In Christ you have been brought to fullness.”
The problem is not your lack but your unbelief. If you pray, “God, please make me righteous and holy,” you are no longer continuing in faith. You are giving voice to unbelief and contradicting his word, which says you are complete in him.
[Extracted from chapter 18, “What does it mean to continue in the faith?” in The Gospel in Twenty Questions]