Any and every believer is already holy by virtue of the fact that he's been SET APART by God for Himself. God has already called us OUT of the multitude: we are holy unto the Lord. Living the 'APART life' is a different thing and it is called holy living. It is not BEING HOLY: it is LIVING HOLY.
For THE TEMPLE OF GOD IS HOLY (sacred to Him) and THAT [TEMPLE] YOU [THE BELIEVING CHURCH AND ITS INDIVIDUAL BELIEVERS] ARE. (1 Corinthians 3:17 AMP)
You cannot accept that you are God's temple and disagree you are holy. God cannot have an UNHOLY TEMPLE. He is the one who SANCTIFIES His temple.
This brings us to some popular misconceptions about sanctification. To sanctify means to make holy: to "holify"something. Whatever process it takes to make a thing holy is sanctification and the state is called sanctity or holiness.
Now if every believer is HOLY, it means they ALL have undergone the sanctification process. Therefore there is no unsanctified believer.
Elect according to the foreknowledge of God the Father, THROUGH SANCTIFICATION OF THE SPIRIT, unto obedience and sprinkling of the blood of Jesus Christ: Grace unto you, and peace, be multiplied. (1 Peter 1:2 KJV)
So you cannot be "Elect" or chosen without sanctification. His choice of you made Him call you APART.
But we are bound to give thanks alway to God for you, brethren beloved of the Lord, because God hath from the beginning CHOSEN you to salvation through SANCTIFICATION of the Spirit and belief of the truth (2 Thessalonians 2:13 KJV)
And now, brethren, I commend you to God, and to the word of his grace, which is able to build you up, and to give you an inheritance among all THEM WHICH ARE SANCTIFIED. (Acts 20:32 KJV)
So the believers are generally called "them that are sanctified"
Can you see that sanctification is not when after salvation you pray and pray and try your best to sin no more? Sanctified is rather who you are!
1Co 6:11 And such were some of you: but ye are washed, BUT YE ARE SANCTIFIED, but ye are justified in the name of the Lord Jesus, and by the Spirit of our God.
Yes, there are believers who commit sin! But God does not change the name He calls you even when you don't seem to live up to the honour of that name. He kept calling Abraham father of many nations even when He had no child. He'll maintain that name until you finally realize it and you're transformed by the renewing of your mind. The earlier you accept His verdict, the earlier you live up to it. He believes in you: you are HOLY unto Him.
But of him are ye in Christ Jesus, who of God is made unto us wisdom, and righteousness, and sanctification, and redemption:
(1 Corinthians 1:30 KJV)
Finally, you are not your own. Your Owner says you are holy. "Shall the thing formed say to him that formed [it], Why hast thou made me thus?". This holiness is not your own. Glorify God for it and live worthy of it.
But God has given you a place in Christ Jesus, through whom God has given us wisdom and righteousness and salvation, and MADE US HOLY (1 Corinthians 1:30 BBE)
But God has brought you into union with Christ Jesus, and God has made Christ to be our wisdom. By him we are put right with God; we become God's holy people and are set free. (1 Corinthians 1:30 GNB)
You are God's children. He sent Christ Jesus to save us and to make us wise, acceptable, and HOLY. (1 Corinthians 1:30 CEV)





