Perhaps you're not qualified to speak for everybody, who, indeed, flees sin, but in being honest of the corruptible nature that persists, finding it always a lesson in avoiding a lack of humility and throwing stones at others' church or faith experiences they have no real knowledge of? So you are a Christian, you are, therefore, without sin in your flesh? If you said so, would you or would you not be a liar?
What is it you are actually saying?
You allude to 1Joh 1:8 which says...
1Jn 1:8 If we say that we have no sin, we deceive ourselves, and the truth is not in us.
...and you use that allusion as evidence that a Christian is sinning, you also add that to deny such a thing implies one is a liar.
Yet that is not what that verse is teaching. No it isn't. 1Joh 1:8 is one of the most abused verses in the Bible.
John makes that statement within the context of "coming clean with God and walking in the light." What John means is "sin to our account" or in other words "to deny that we ever sinned."
That is why he reinforces those words in verse 10 where he says...
1Jn 1:10 If we say that we have not sinned, we make him a liar, and his word is not in us.
Look at the whole passage in context...
1Jn 1:5 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.
1Jn 1:6 If we say that we have fellowship with him, and walk in darkness, we lie, and do not the truth:
1Jn 1:7 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.
1Jn 1:8 If we say that we have no sin, we deceive ourselves, and the truth is not in us.
1Jn 1:9 If we confess our sins, he is faithful and just to forgive us our sins, and to cleanse us from all unrighteousness.
1Jn 1:10 If we say that we have not sinned, we make him a liar, and his word is not in us.
1Jn 2:1 My little children, these things write I unto you, that ye sin not. And if any man sin, we have an advocate with the Father, Jesus Christ the righteous:
1Jn 2:2 And he is the propitiation for our sins: and not for ours only, but also for the sins of the whole world.
1Jn 2:3 And hereby we do know that we know him, if we keep his commandments.
1Jn 2:4 He that saith, I know him, and keepeth not his commandments, is a liar, and the truth is not in him.
1Jn 2:5 But whoso keepeth his word, in him verily is the love of God perfected: hereby know we that we are in him.
1Jn 2:6 He that saith he abideth in him ought himself also so to walk, even as he walked.
John is defending against the notion that one can be abiding in God in the spirit yet sinning in the flesh at the same time. He was refuting the Gnostics teaching of dualism by alluding to the fact that we have to come clean with God in confession and also WALK in the light as He is in the light. Thus the children of God KNOW that they abide in Him because they KEEP HIS WORD.
That is the very opposite of the wretched man message preached in most churches. Very few churches will teach that, instead they preach a package salvation which people trust in whilst they remain sinners.
This "corruptible nature which persists" whereby you have "sin in your flesh" is not a Christian teaching. That teaching has its origin in Neo-Platonism and Gnosticism in which it was taught that the material world (ie. matter) was corrupted and therefore human flesh imprisoned the virtue of the soul. Thus they taught that one would be "sinning in the flesh" but not "sinning in the spirit."
John refuted this notion by teaching that actual conduct reveals to whom we belong to.
1Jn 3:6 Whosoever abideth in him sinneth not: whosoever sinneth hath not seen him, neither known him.
1Jn 3:7 Little children, let no man deceive you: he that doeth righteousness is righteous, even as he is righteous.
1Jn 3:8 He that committeth sin is of the devil; for the devil sinneth from the beginning. For this purpose the Son of God was manifested, that he might destroy the works of the devil.
1Jn 3:9 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.
1Jn 3:10 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.
The children of God are manifest in that they do not sin but produce the fruit of righteousness in their lives. The implanted word of God does not lead us to sin and we KEEP OURSELVES through abiding in that implanted word wholeheartedly.
1Jn 5:18 We know that whosoever is born of God sinneth not; but he that is begotten of God keepeth himself, and that wicked one toucheth him not.
John also makes the distinction between "sin unto death" and "sin not unto death." It is only rebellion which kills not falling short due to ignorance.
1Jn 5:16 If any man see his brother sin a sin which is not unto death, he shall ask, and he shall give him life for them that sin not unto death. There is a sin unto death: I do not say that he shall pray for it.
1Jn 5:17 All unrighteousness is sin: and there is a sin not unto death.
Which is why it is "obedience unto righteousness" or "sin unto death" as taught by Paul.
Rom 6:16 Know ye not, that to whom ye yield yourselves servants to obey, his servants ye are to whom ye obey; whether of sin unto death, or of obedience unto righteousness?