Sanctification is different than justification. In justification, our effort and works are unnecessary and unwelcome, repugnant to God; in sanctification, they are essential and celebrated, commanded by God. Justification is unchanging, set once for all in the heavens; sanctification is dynamic, constantly changing based in part on our faithfulness or faithlessness to God. Justification inevitably leads to sanctification; without evidence of sanctification, there should be no assurance of justification. There are no degrees of justification: we are either justified or we are not. There are infinite degrees of sanctification, based on how conformed we are to the infinitely high standard of Christ.
An Infinite Journey, Andrew Davis