From “Steps to Christ” chapter 13 (page 115):
The children of God are called to be representatives of Christ, showing forth the goodness and mercy of the Lord. As Jesus has revealed to us the true character of the Father, so we are to reveal Christ to a world that does not know His tender, pitying love.“As Thou hast sent Me into the world,” said Jesus, “even so have I also sent them into the world.” “I in them, and Thou in Me; . . . that the world may know that Thou hast sent Me.” John 17: 18, 23. The apostle Paul says to the disciples of Jesus, “Ye are manifestly declared to be the epistle of Christ,” “known and read of all men.” 2 Corinthians 3:3, 2.In every one of His children, Jesus sends a letter to the world. If you are Christ’s follower, He sends in you a letter to the family, the village, the street, where you live. Jesus, dwelling in you, desires to speak to the hearts of those who are not acquainted with Him.Perhaps they do not read the Bible, or do not hear the voice that speaks to them in its pages; they do not see the love of God through His works. But if you are a true representative of Jesus, it may be that through you they will be led to understand something of His goodness and be won to love and serve Him.”
From John 17:17:
Sanctify them through thy truth; thy word is truth.
Sanctification is the process that follows justification and the spiritual birth of the sinner. At the time of justification, we are actually placed in Christ, Him standing as a substitute while covering us with His righteousness before the Father. Through the process of sanctification, Christ fills our minds and bodies with the Holy Spirit. Justification means we are in Christ, sanctification means Christ is in us. As opposed to justification, which is a statement of fact, a declaration, and done in an instant, sanctification is the work of a lifetime. The process is complete only when we give our final breath, or at the return of our Saviour, whichever comes first.
While it can be steeped in theology, the process of sanctification is simple. The first step is Christ, through the Holy Spirit, convicts us of sin. The next step is Christ helps us to repent of the sin. Third step is Christ removes the sin from our lives. Repentance means to change the mind. God gifts us repentance following rebirth, changing our mind to no longer desire sin, and we are convinced that our actions are sinful before God. Where once we’d sin daily, enjoying the action and result, the sin starts to become abhorrent and decreases in frequency. Truly, we are never free from sin, but its occurrence becomes extremely rare and extremely unwanted. This change may be almost imperceptible to an observer, because small changes take place of a long time, but the end result is always a transformation of the sinner’s character into a more Christ-like character. In time, the world bears witness to the work of God in the believer. Good fruit is made manifest.
An example from my own life is fleshly lust. I used to really enjoy looking at women other than my wife. Many times my wife would even encourage this behaviour. After being born again, Christ began convicting me that these actions are sinful. After repenting and turning our eyes to the cross of Christ, God is quick to forgive and forget. The result after 2+ years is that whereas I used to ogle any woman that crossed my field of view, I am now annoyed if my eye even so much as wonders to another woman other than my wife. Do I still look? Sometimes, but I no longer find enjoyment in the act. It’s become a repulsive action that happens in a moment of lapse, once in a while.
The nature of repentance is such that the sin no longer has any hold on our minds. We no longer desire to do the thing, and when we do it, we are repulsed by it. Our carnal bodies will still win sometimes against the repented mind, but the act will not bring enjoyment as it once did. We don’t sin joyfully, we sin sorrowfully, and this is the new nature that God creates in us after justification. However, we do not become less sinful in our nature, just more dependent on God. We retain the sinful nature, but abhor it more and more.
During the sanctification process, Christ will go through each sin in our lives and cleanse us of them one by one in the way outlined above. At the same time, He will also instill into us the gifts of the Holy Spirit, through which we show God’s character to those around us. Love, joy, peace, longsuffering, gentleness, goodness, faith, meekness, and temperance. God gives us an unquenchable desire for these things, to set Christ forth before the world through our witness of God’s character.
The appearance of these gifts in our lives happens almost in an opposite way of the cleansing of sin from us. At first, these gifts are only subtle, not noticeable. As time goes by, God brings them forth more evidently and allows us to practice these skills. In this way, the gifts of the Spirit grow in us and become second-nature. Our characters and actions will slowly start to mirror God’s character and actions, for we are to fulfill His will in this world. We will feel a small sampling of what God feels for the world, and we will love them almost as much as God loves us.
This is how sanctification works. On one side, Christ eliminates sinful desires from our hearts. On the other side, Christ instills holy desires into our hearts. The heart of stone becomes a heart of flesh. We obey God’s will and embody His character for those around us to see. We are the witnesses of His might, mercy, and unending grace to a fallen world.