Although many Christians will work and strive to produce good fruit, sometimes they end up back under a system of works or a modernized version of the Mosaic law. There was fruit involved for those Jewish people who were under the law of works, but it brought fruit for death. In the new covenant of Jesus Christ, we have been freed into the new way of life in the Spirit. Instead of working to produce fruit through our efforts, we simply rest and abide in Christ and the Spirit bears His fruit through us.
As we recognize the identity of righteousness that belongs to us in Jesus Christ, we can put away our own efforts and rest in him. Before the cross, the Jewish people were in bondage to the Mosaic law as it demanded a perfection the people could not attain. Their works were based on pursuing their own righteousness because they did not understand God's righteousness. We are declared perfected, justified and sanctified. As the Apostle Paul stated, "For through the law I died to the law, so that I might live to God."
In the world of Christian legalism, justification may be presented as a free gift, but sanctification is often taught to be a progressive process that we must work at in order to possess or experience. This misunderstanding of what was accomplished for us through the work of the cross will eventually lead people back into a mentality of works and guilt, or self-righteousness and boasting in themselves. Jesus has (already) become our sanctification, and it cannot be defined outside of what he did on our behalf.
The word "sanctified" means "set apart," "purified," "made holy." Sanctification is a matter of being set apart to God, by His gift, by grace through faith. This is a finished work. All believers are heaven-ready right now at this very moment, because they have been sanctified once and for all!