1 John 3:9-10 Whosoever is born of God doth not commit sin; for his seed remaineth in him: and he cannot sin, because he is born of God. In this the children of God are manifest, and the children of the devil: whosoever doeth not righteousness is not of God, neither he that loveth not his brother.
Who is the only One, The Only Begotten Son of God? Of course it is Jesus Christ the Son of God and He is the only human that did not, cannot, and never will sin.
So it is the seed of Jesus Christ that is born again in the believer that cannot sin, that sinless perfection can only be manifested in the believer by the Born Again experience of the incorruptible Seed of the Father which is Jesus Christ, He being the only one who has not sinned and never would.
1 Peter 1:22-25 Seeing ye have purified your souls in obeying the truth through the Spirit unto unfeigned love of the brethren, see that ye love one another with a pure heart fervently: Being born again, not of corruptible seed, but of incorruptible, by the word of God, which liveth and abideth for ever. For all flesh is as grass, and all the glory of man as the flower of grass. The grass withereth, and the flower thereof falleth away: But the word of the Lord endureth for ever. And this is the word which by the gospel is preached unto you.
Both passages are pointing to loving your brother. This is the manifestation of God in the believer that Jesus Christ gave another commandment "Love one another as I have loved you".
Total sanctification is Jesus Christ in me. Progressive sanctification is by Him being the power and labor to work and do of His good pleasure which is to sanctify us in Himself and make us sons of God and a purified Bride.
Who is sanctified completely? The Christ in me. Who is made unto me sanctification? The Christ in me. Who is making me sanctified? The Christ in me.
1 Corinthians 1:29-31 That no flesh should glory in his presence. But of him are ye in Christ Jesus, who of God is made unto us wisdom, and righteousness, and sanctification, and redemption: That, according as it is written, He that glorieth, let him glory in the Lord.
Who is faithful and just to forgive me if I sin. God in all His Glory, when I agree with Him for my sin which is manifest if I sin, Grace abounds even more and I am forgiven in Christ evermore.
Please read all of this passage of the Word of God who Is Jesus Christ.
1 John 1:1-10 That which was from the beginning, which we have heard, which we have seen with our eyes, which we have looked upon, and our hands have handled, of the Word of life; (For the life was manifested, and we have seen it, and bear witness, and shew unto you that eternal life, which was with the Father, and was manifested unto us;) That which we have seen and heard declare we unto you, that ye also may have fellowship with us: and truly our fellowship is with the Father, and with his Son Jesus Christ. And these things write we unto you, that your joy may be full. This then is the message which we have heard of him, and declare unto you, that God is light, and in him is no darkness at all. If we say that we have fellowship with him, and walk in darkness, we lie, and do not the truth: But if we walk in the light, as he is in the light, we have fellowship one with another, and the blood of Jesus Christ his Son cleanseth us from all sin. If we say that we have no sin, we deceive ourselves, and the truth is not in us. If we confess our sins, he is faithful and just to forgive us our sins, and to cleanse us from all unrighteousness. If we say that we have not sinned, we make him a liar, and his word is not in us.
Am I sanctified completely? Yes in Christ. Am I being sanctified? Yes in Christ. Will I be totally sanctified? Yes in Christ. By His mighty resurrection Power that worketh in me mightily.
Colossians 1:27-29 To whom God would make known what is the riches of the glory of this mystery among the Gentiles; which is Christ in you, the hope of glory: Whom we preach, warning every man, and teaching every man in all wisdom; that we may present every man perfect in Christ Jesus: Whereunto I also labour, striving according to his working, which worketh in me mightily.
IN Christ, who is my sanctification: Phillip