Listen again to Sinclair Ferguson in his chapter in Christian Spirituality:
Because sanctification involves the imitation of Christ, it’s goal is true humanity, regained through Christ. That this is the heart of the Reformed doctrine of sanctification cannot be overstressed. Sanctification is radical humanization. It means doing the “natural” thing spiritually, and the “spiritual” thing naturally. “What a redeemed soul needs,” wrote Abraham Kuyper, “is human holiness.” Restoration of the image of God to true humanity is God’s ultimate purpose for his people. The model and source for this transformation are both found in the humanity of Jesus Christ, the one truly sanctified human.