What is Sanctification?

Three Aspects of Sanctification:

POSITIONAL: (1 Cor. 1:2, 30). All believers were so sanctified as saints, the youngest as well as the oldest, the most carnal as well as the most spiritual. As God sees us in Christ (1 Cor. 1:2 with Phil 1:1) (Bible.org, 2009).
EXPERIANTIAL: Depends upon our knowledge of and faith in our position in Christ (Rom. 6:1-11), converting our position into experience. Progressive, changeable, depends upon yieldedness, & God’s will (Rom. 6:13). As we are in our conduct (2 Thess. 2:13) (Bible.org, 2009).
FINAL: When we see the Lord and are made like Him sinless, sickless, deathless (1 Cor. 4; 15:54; 1 Jn. 3:2). Static, unalterable, Will result in our state in eternity (Phil. 3:21). As we shall be in glory (Rom 8:29; 1 Cor. 15:49) (Bible.org, 2009).
True Sanctification is PASSIVE and ACTIVE. Passive is when we are sanctified by God’s grace through the washing of new birth. Paul explains it as follows: “But when the goodness and loving kindness of God our Savior appeared, he saved us, not because of works done by us in righteousness, but according to his own mercy, by the washing of regeneration and renewal of the Holy Spirit” (Titus 3:4-5). This is positional sanctification where we are placed in Christ (Rom. 6) and seen as Holy by God through His Son, because no unholy thing will enter heaven. We do not contribute anything to this and it is wholly a work of God through the Spirit whereby we are placed in Christ. Paul explains this as someone being resurrected from the dead: “But God, being rich in mercy, because of the great love with which he loved us, even when we were dead in our trespasses, made us alive together with Christ – by grace you have been saved” (Eph. 2:4-5).
True Sanctification is also ACTIVE as we work out our salvation. We have received a new nature as a free gift. We have received the indwelling Holy Spirit as a free gift. We cannot deserve this by choice or obeying something. This is a complete initial work of God. But the Bible teaches an active responsibility with this new nature we have received. Therefore Paul wrote to the Philippians “work out your salvation” (Phil 2:12). He also give the reason why we need to work it out. He says: “because it is God who works in you to will and to act according to his good purpose” (Phil. 2:13). God has a plan for every chid of His and that is to be separated and set apart from the world. “Therefore go out from their midst, ​​​​​​​and be separate from them, says the Lord, ​​​​​​​and touch no unclean thing; ​​​​​​​then I will welcome you, ​​​​and I will be a father to you, ​​​​​​​and you shall be sons and daughters to me, ​​​​​​​says the Lord Almighty” (2 Cor. 6:17-18) ​​​ This is a process and we are not like this the moment we are born again. It takes time to grow in the knowledge of Christ. When we are born again, the seed of faith as small as a mustard seed is planted in us. The vail is now torn and as we behold Christ through the Word, we are changing daily from glory to glory. “And we all, with unveiled face, beholding the glory of the Lord, are being transformed into the same image from one degree of glory to another. For this comes from the Lord who is the Spirit” (2 Cor 3:18).
Unfortunately there are also many false teachings around sanctification. The Bible teaches a balanced approach to most essential doctrines. Extremes has always existed. The human sinful nature is prone to extremes to either side of the balanced view of the Bible. There are those who will teach we can become completely holy this side of the grave without sinning at all. This group over emphasise active sanctification to such an extend that sanctification becomes a righteousness they must attain and work for. They forget the passive part where we are initially sanctified by the washing and cleansing of the new birth by the Holy Spirit. Every fleshly dead make them unholy and they must continually strive to be clean and this is a self effort and process. They try to abstain from every worldly thing, because it makes them unclean and they strive to perfection. It is self made holiness, because it forgets the passive part of sanctification whereby we are in Christ seen as completely Holy by God through Jesus Christ.
Then there is the other extreme where people over emphasise passive sanctification and they reject the active responsibility the child of God has to be separated from the world by the daily sanctification of the Holy Spirit as we lay off sin and commit more and more to the leading of the Holy Spirit. They over emphasise the passive part of sanctification to such an extend that it does not matter how a person live. They ignore the progressive nature of sanctification. This leads to the abuse of grace which Paul wrote about when he said: “Are we to continue in sin that grace may abound? By no means! How can we who died to sin still live in it?” (Rom 6:1-2). The end result of this extreme overemphasising the grace of God lead to abuse of God’s grace, because when I sin, it has no effect on me, because I am always Holy. Although this is true in a sense, the true child of God will also show the deepest desire given by the presence of the Holy Spirit in his heart, to hate sin and love His Father. He wants to please his Father with everything in him.
The balanced view of sanctification from the Bible contain a balance of both passive sanctification and active sanctification. The child of God is Holy because God has made him Holy in the new birth when He united him through the Spirit with his Son Jesus Christ. This is why he can enter the Holy of Holies. But the child of God also has a responsibility to work out his salvation by growing in the knowledge of Christ, by being separated from the world ann following Jesus, by laying down sin and continually live all the more in obedience to the Holy Spirit. This Paul confirmed in Galatians 5:25 when he said: “live by the Spirit…walk by the Spirit”. Both the passive and active components of sanctification can be seen in perfect balance in the following verses: “And those who belong to Christ Jesus have crucified the flesh with its passions and desires. If we live by the Spirit, let us also walk by the Spirit” (Gal. 5:24-25). In the first instance we see the passive part where a believer who belong to Christ has been crucified and made Holy by the cross of Christ. But in verse 25 we see the active part where we have to obey and follow the lead of the Spirit which sanctify us daily not to follow the desire and lusts of the flesh. Look how Paul put it: “But I say, walk by the Spirit, and you will not gratify the desires of the flesh. For the desires of the flesh are against the Spirit, and the desires of the Spirit are against the flesh, for these are opposed to each other, to keep you from doing the things you want to do” (Gal 5:16-17).
 
References:
1. Bible.org. 2009. Sanctification. https://bible.org/illustration/sanctification.