It is really quite amazing to see so much confusion about salvation. Yes, there are some who delude themselves into believing that sinless perfection is attainable in this life, while others believe that salvation can be lost. Both are errors. So we need to see what the Bible says:
1. Even after someone is saved, the old sin nature -- "the flesh" -- is not eradicated. Therefore there is a conflict between the flesh and the Spirit: This I say then, Walk in the Spirit, and ye shall not fulfil the lust of the flesh. For the flesh lusteth [conflicts] against the Spirit, and the Spirit against the flesh: and these are contrary the one to the other: so that ye cannot do the things that ye would. (Gal 5:16,17)
2. Christians who deny that they sin deceive themselves and make God a liar: 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. (1 John 1:8-10)
3. Christians are commanded to live soberly, righteously, and godly in this present world: For the grace of God that bringeth salvation hath appeared to all men, teaching us that, denying ungodliness and worldly lusts, we should live soberly, righteously, and godly, in this present world (Titus 2:11,12)
As we can see those who are saved do have the imputed righteousness of Christ, but because of the flesh they can fall into sin. Therefore they must examine themselves, confess their sins, and repent. But the constant goal of every believer must be righteousness and holiness.
Salvation is the gift of eternal life after God justifies a sinner by His grace. Therefore salvation can never be lost. If a Christian persists in sinning there are other remedies which God applies.