Sanctification is inextricably connected to the crucifixion of Jesus Christ. “It is finished!” also applies to sanctification: Just as the blood of the Passover lamb separated the Israelites from the Egyptians, so the sacrifice of Jesus Christ set up a partition between the church of God and the world with its sin. Furthermore, Christ gives us His holiness so that God sees us in His Son as “sanctified”, as holy people.
By that will we have been sanctified through the offering of the body of Jesus Christ once for all. (Hebrews 10:10)
For by one offering He has perfected forever those who are being sanctified. (Hebrews 10:14)
But of Him you are in Christ Jesus, who became for us wisdom from God – and righteousness and sanctification and redemption. (1 Corinthians 1:30)
For both He who sanctifies and those who are being sanctified are all of one, for which reason He is not ashamed to call them brethren. (Hebrews 2:11)
We are sanctified through God’s Word and the Holy Spirit.
Sanctify them by Your truth. Your word is truth. (John 17:17)
But we are bound to give thanks to God always for you, brethren beloved by the Lord, because God from the beginning chose you for salvation through sanctification by the Spirit and belief in the truth. (2 Thessalonians 2:13)
Walk in the Spirit, and you shall not fulfil the lust of the flesh. (Galatians 5:16)
Our Heavenly Father’s chastisements also sanctify us.
We know that all things work together for good to those who love God, to those who are the called according to His purpose. (Romans 8:28)
For they (our fathers) indeed for a few days chastened us as seemed best to them, but He for our profit, that we may be partakers of His holiness. Now no chastening seems to be joyful for the present, but painful; nevertheless, afterward it yields the peaceable fruit of righteousness to those who have been trained by it. (Hebrews 12:10-11)