I believe Cobus is arguing that you are already sanctified. There's no striving involved, there is no process - you are either sinless, or you are not. Saved, or not. One sin, you have shown that you were never truly justified, you were never sanctified, God's Spirit never dwelt in you.
well, we may be reading differently, but even then, it is quite possible to be Sanctified in this life. We are called to be sanctified. The Apostle Paul made this quite clear........
1st Corinthians 2:7) But we speak the wisdom of God in a mystery, even the hidden wisdom, which God ordained before the world unto our glory:
8 .) Which none of the princes of this world knew: for had they known it, they would not have crucified the Lord of glory.
9 .) But as it is written, Eye hath not seen, nor ear heard, neither have entered into the heart of man, the things which God hath prepared for them that love him.
10 .) But God hath revealed them unto us by his Spirit: for the Spirit searcheth all things, yea, the deep things of God.
11 .) For what man knoweth the things of a man, save the spirit of man which is in him? even so the things of God knoweth no man, but the Spirit of God.
12 .) Now we have received, not the spirit of the world, but the spirit which is of God; that we might know the things that are freely given to us of God.
13 .) Which things also we speak, not in the words which man's wisdom teacheth, but which the Holy Ghost teacheth; comparing spiritual things with spiritual.
14 .) But the natural man receiveth not the things of the Spirit of God: for they are foolishness unto him: neither can he know them, because they are spiritually discerned.
15 .) But he that is spiritual judgeth all things, yet he himself is judged of no man.
16 .) For who hath known the mind of the Lord, that he may instruct him? But we have the mind of Christ.
3:1) And I, brethren, could not speak unto you as unto spiritual, but as unto carnal, even as unto babes in Christ.
2 .) I have fed you with milk, and not with meat: for hitherto ye were not able to bear it, neither yet now are ye able.
3 .) For ye are yet carnal: for whereas there is among you envying, and strife, and divisions, are ye not carnal, and walk as men?
The carnal Christian is surely saved, yet is not sanctified. Sanctification occurs when the Holy Spirit takes up residence in our hearts......His indwelling presence is what sanctifies us.