What is sanctification?

TL;DR:

To be sanctified means to be “set apart for a specific purpose or use.” Our sanctification is the process by which our salvation transforms us into Christ’s likeness so we can better reflect Him.

Many Christians, those who have been saved by grace through faith in Jesus’ death and resurrection for the forgiveness of sins, refer to a progression of justification, sanctification, and glorification. Justification refers to the fact that believers have been deemed legally righteous. With Christ's death and resurrection, our sin was forgiven and we are now pure before God (2 Corinthians 5:21; Romans 5:1; Romans 6). While we know that our salvation is complete, there are still aspects of our salvation that are being worked out. We are righteous, and we are also becoming righteous. This "becoming righteous" is referred to as sanctification. Sanctification is where our present realities fall in line with our eternal status.

from the old testament

While sanctification is specifically a term referring to salvation under the New Covenant, most followers of YHWH in the Old Testament can be said to have been on a journey of sanctification, growing in character as they walked out their life with God. For example:
Noah found favor with God and obeyed His commands, even when it required great faith (Genesis 6:9, 22; see also Hebrews 11:7).
Abraham grew in faith and obedience, trusting God’s promises despite significant challenges (Genesis 12:1-4; Genesis 22:12; see also Romans 4:20-21).
Isaac trusted God’s provision and maintained the covenant relationship passed down by Abraham (Genesis 26:2-5).
Jacob matured over time, transforming from a deceiver to a man who wrestled with God and received a new name, Israel (Genesis 32:28; Genesis 35:10-12).
Through trials, Joseph remained faithful to God and developed into a man of wisdom, integrity, and forgiveness (Genesis 39:2-4; Genesis 50:20).
Moses went from hesitation and self-doubt to becoming a faithful leader of God’s people (Exodus 3:11-12; Numbers 12:3; see also Hebrews 11:24-28).
Despite his sins, David demonstrated repentance and grew in his understanding of God’s mercy and justice (1 Samuel 13:14; Psalm 51:10-12; see also Acts 13:22).

from the new testament

Jesus prayed for our sanctification (John 17:17).
We are sanctified by the Holy Spirit (Romans 15:16).
We are sanctified in Christ Jesus (1 Corinthians 1:2; 6:11).
We are daily becoming the righteousness of God (2 Corinthians 5:21).
Sanctification is about leaving our old lives in exchange for His (Ephesians 4:22-24).
Christ sanctifies the church with His word (Ephesians 5:26).
We are called to work out our salvation with fear and trembling (Philippians 2:12).
We are being built up into Christ (Colossians 2:7; 1 Peter 2:5).
We are sanctified through Christ’s death on the cross (Hebrews 10:10, 14).

implications for today

In one sense, the Christian life is all about sanctification. Christ is finishing the good work that He began in us (Philippians 1:6). We are continually learning to follow God's ways and discard our sinful natures (Ephesians 4:22-24; Colossians 3:5-17). Paul wrote to the church in Ephesus, "I therefore, a prisoner for the Lord, urge you to walk in a manner worthy of the calling to which you have been called" (Ephesians 4:1). We have been declared holy and now attempt to live holy lives (Matthew 5:48). As Christians, we are to cooperate with God's work in us. He refines and prunes us (Zechariah 13:9; Malachi 3:2; Isaiah 48:10; 1 Peter 1:7; John 15:2), and sanctification is what we call that work. The life of faith is not easy as God exposes our sin and need for Him, but it is deeply rewarding as we become more like Christ and reflect His love to the world. Sanctification calls us to daily surrender, trusting in God's power to transform us as we obey Him step by step. As we grow, we testify to His grace, pointing others to the One who makes all things new. Let us press on with hope and perseverance, knowing that God is faithful to complete what He has started at salvation.

understand

Sanctification means being set apart for God’s purpose
Sanctification is being transformed into Christ’s likeness and happens after salvation.
Sanctification is a process empowered by the Holy Spirit.

reflect

How have you seen God refining or transforming you in your daily life as part of the sanctification process?
In what areas of your life do you feel challenged to leave behind old ways and live more like Christ?
What does it look like to intentionally cooperate with the Holy Spirit’s work of sanctification in your heart and mind?

engage

What is the connection between our salvation and our sanctification?
What is the purpose and process of our sanctification?
How does the process of sanctification demonstrate God’s faithfulness to complete the good work He began in us?