“That Christ may dwell in your hearts by faith; that ye, being rooted and grounded in love, may be able to comprehend with all saints what is the breadth, and length, and depth, and height; And to know the love of Christ, which passeth knowledge, that ye might be filled with all the fulness of God.” (Ephesians 3:18-19)
When Christ comes to dwell in our hearts we have been set on a wonderful journey that ends with the glorious destiny of being as He is. No saint sanctifies themselves. Once we are in Christ and Christ is in us we are holy. Both sanctification and justification are gifts of God, received by faith. That is our beginning. Now the holy God who lives within us teaches us to walk in holiness.
There are depths to holiness that Christ in us would take us to; going beyond what we don’t do and becoming as He is. Yes, we must cooperate with Him in learning to hate the evil He hates; but we must also love the righteousness He loves. The holiness He desires of us is found in action and attitude. To worship the Lord in the “beauty of holiness” is to walk in the very Spirit of Christ. Growing in doctrinal knowledge, abounding in service to our Lord, is all well and good, but it profits us nothing if we are not becoming more like Jesus in our love toward God and man.
Those who want to be holy simply want to be like Jesus. He is our Sanctification. (1 Cor. 1:30) No matter how saintly you appear to men, if you are not becoming more and more like Jesus in your heart, you are falling short in the sight of Him who has called you to be holy, even as He is holy.