At salvation, the person who has been granted repentance and faith in Christ finds that the desires of his mind and heart have been transformed to desire the pursuit of righteousness to which God calls us (Matthew 6:33).
We will not be perfect this side of Heaven, however, and we find ourselves undergoing a constant process of sanctification.
Philippians 2:12-13 presents the paradox of sanctification. While it is a work of God, sanctification is worked out by men through the means provided to them by the Father:
So then, my beloved, just as you have always obeyed, not as in my presence only, but now much more in my absence, work out your salvation with fear and trembling; for it is God who is at work in you, both to will and to work for His good pleasure.
How, then, is sanctification a consequence of the cross?
Those who have been redeemed by the blood of Christ, who stand legally justified before the Father, are new creatures.
The old things passed away, behold, new things have come. (2 Corinthians 5:17)
Paul’s discussion of the new man in this verse is closely tied to the reconciliation of men to God that was wrought by Jesus on the cross.
Think for a moment of Christ upon the cross. He who was sinless bled and died, bearing the wrath of God for the sins of all who would believe (Romans 5:6-11). What He endured, you deserve, and yet His death satisfied the wrath of God so that by believing in Him you may inherit eternal life (John 3:36).
Why, then, would you desire to actively and willingly engage sin? Why would you delight in that for which Christ died (Ephesians 5:3-12)?
Salvation was fully accomplished on the cross. Sanctification is the fruit of that salvation worked out practically in the believer’s life. Surely the man who has been saved by God should desire to be sanctified by God.