… purify for Himself His own special people… (NKJV)
What Is Sanctification?
This is a huge question. Go to Amazon.com, search for sanctification, and you will find many books on the subject. Not all of them are Christian books; the topic is relative to Judaism and even Buddhism. Don’t get your hopes up that it will be exhaustively explained in this brief blog. This will only cover a few points at a very high level.
Sanctification, holiness, and purity are related; sanctify is to make or declare to be holy. Holy is to be “set apart for God, to be, as it were, exclusively his; in a moral sense, pure, sinless, upright, holy.” As such, even inanimate objects were declared holy in the Old Testament. As applied to people, we are set aside from the world to be a unique people (1 Peter 2:9). Sanctification is the process of being separated from sin and becoming more and more pure. Holy is the eventual behavioral result of sanctification on one hand and one the other it is a position or state because of the declaration of being holy.
For this is the will of God, your sanctification. (1 Thess 4:3 NKJV)
Since it is God’s will for us to be sanctified, it should be a huge concern for anyone who seeks to do His will. Titus 2:14 reveals just how much of His will it is because He is the one who purifies us. Since God is holy, only holy people will be able to see Him (Heb 12:14). Since we are not holy, the first concept of holiness or sanctification is that He purifies us. Sanctification starts with God, not with us. Through the blood of Jesus, God justifies us and declares us to have His righteousness (Rom 3:25-26). This leads to sanctification (Rom 6:22). If we were able to sanctify ourselves, then there would not have been a need for Jesus to die on the cross (Gal 2:21).
Make them holy by your truth; teach them your word, which is truth. (John 17:17 NLT)
… Christ loved the church. He gave up his life for her to make her holy and clean, washed by the cleansing of God's word. He did this to present her to himself as a glorious church without a spot or wrinkle or any other blemish. Instead, she will be holy and without fault. (Eph 5:25-27 NLT)
We are made holy by God’s Word. Jesus said it and Paul explained it. Notice that in both Jesus’ words and Paul’s, the tool used to make us holy is God’s Word. However, Paul also clarifies that Jesus had to give up his life so that we could be made holy. Paul presents this as an accomplished fact once we’ve been washed by the Word. Jesus provides the potential and His Word completes the task. When does this occur? It happens at the time of our salvation. We are declared holy and righteous. This is similar to the vessels that were used in the tabernacle. They were sprinkled with blood and then declared holy. Were they really any different than before? Not physically, but they were consecrated or set aside for holy purpose. In the same way, when we are saved, we are sprinkled with the blood of Jesus and declared holy, set aside for God’s use. We are not physically any different than before our salvation. Spiritually, we are a totally different person (2 Cor 5:17). As far as being a better person, everyone grows in practical or behavioral holiness at a different rate. And that is the second part of sanctification.
Being Made Holy
Not that I have already obtained it, or have already become perfect, but I press on in order that I may lay hold of that for which also I was laid hold of by Christ Jesus. (Phil 3:12 NASB)
If you would think anyone could claim to have become the epitome of holiness in this life, it would have been Paul, who wrote a significant portion of the New Testament. But he had personal problems with others (Acts 15:36-41). He admitted that God gave him a physical affliction to keep him from being conceited (2 Cor 12:7). Philippians 3:12 expressed his awareness that personal behavioral holiness was something that is a work that we participate in all of our lives.
You were taught, with regard to your former way of life, to put off your old self, which is being corrupted by its deceitful desires; to be made new in the attitude of your minds; and to put on the new self, created to be like God in true righteousness and holiness. (Eph 4:22-24 NIV)
The things we have learned from the world, habits, attitudes, desires, and in some cases cultural values, must be relearned through the Word of God. Paul describes this as putting off the old self and putting on the new self. This is not simply turning over a new leaf, it is a genuine heart change that must begin with surrendering our lives, our wills, our bodies to God in true worship (Rom 12:1). The result of this is a transformation of our entire lives and it starts in our minds (Rom 12:2) as we repent of our old sinful life.
… remembering you in my prayers, that the God of our Lord Jesus Christ, the Father of glory, may give you a spirit of wisdom and of revelation in the knowledge of him, having the eyes of your hearts enlightened, that you may know what is the hope to which he has called you, what are the riches of his glorious inheritance in the saints, and what is the immeasurable greatness of his power toward us who believe … (Eph 1:16-19 ESV)
We must remember that this is a process and while we are declared holy at salvation, changing our behavior is a lifelong task. While Jesus sanctifies us (Heb 2:11), it is through the power of His Holy Spirit. That power is available to us when we call upon Him but not everyone knows that this power for godly living is available. Paul prayed for the saints in Ephesus to understand and use this power that was the same power that raised Jesus from the grave and exalted Him to the right hand of the Father. Think about that and appropriate that power in your own life when you are faced with temptation. There is no need to continue in habitual sin or occasional grievous sins when you have been enlightened to the power available to you to resist. God always has a way out of temptations without sinning (1 Cor 12:13).
Search me, O God, and know my heart; Try me and know my anxious thoughts; And see if there be any hurtful way in me, And lead me in the everlasting way. (Ps 139:23-24 NASU)
Brethren, even if anyone is caught in any trespass, you who are spiritual, restore such a one in a spirit of gentleness. (Gal 6:1 NASU)
We should have David’s attitude and desire to have a clear conscience before God. Let Him convict us of sin and not assume that we have arrived at sanctification. I’m sure that if I take time in God’s Word and prayer, He will point out another area of improvement. If this doesn’t work, He may send another Christian to reveal the sin in my life with gentleness. I would prefer the first but also welcome the second (Ps 141:5) if I’ve thought to highly of myself and have ignored sin that others can see. I pray this is your desire as well.
 Thayer's Greek Lexicon, s.v.” NT:37” (Seattle: Biblesoft, 2006).
 Ibid., s.v. “NT:40”.