You and Icon are saying one must be sinless to be a true christian.
With you view point you must feel that scripture lied about Lot.
Peter made it very clear about Lot and the person who becomes carnal.
2 Peter 2:7 And delivered just Lot, vexed with the filthy conversation of the wicked:
8 (For that righteous man dwelling among them, in seeing and hearing, vexed his righteous soul from day to day with their unlawful deeds
Notice he says Lot was just, he had been justified by Faith, yet he was vexed with the filthy conversation of the wicked, he was just but was as one of them. That righteous man (Lot) dwelt amoung them, seeing and hearing he vexed his righteous soul from day to day. Sounds very much like a just, righteous saved man can fall back into sin. Not as you and ICON and others see a believer must live a sinless life and stay upright through his walk. Either Peter was wrong in saying Lot was a just and righteous man living in sin or your way of thinking might need to be looked at. Lot never fully returned to God he dwelt in caves and had sons by his dughters, yet Peter says He was just and righteous. He was a carnal believer scripture affirms it. Notice agian what Paul said to the Romans in chapter 8: 12 Therefore, brethren, we are debtors, not to the flesh, to live after the flesh.
13 For if ye live after the flesh, ye shall die: but if ye through the Spirit do mortify the deeds of the body, ye shall live.
We are not debtors to the flesh to live after is but i we (Paul is speaking to believers) live after the flesh, sounds a lot like a believer can live after the flesh. The word in the greek for flesh here is sarx of which we see the word carnal (Sarkikos) so again we see believers living in the flesh. Verse 13 if we through the power of the Spirit mortify (put to death) the deeds of the body we will live. Again Paul is addressing believers who live in the sarx (flesh) therefor being Carnal (Sarkikos).
Scripture is quite clear, two apostles both show that true believers can revert back to living in the flesh. They don't live sinless lives as you and ICON want to say, they don't live perfect lives, they live in sin and are saved. We all sin and come short of God's glory. Many of us as Christians never revert fully back into sin, as you seem to think but scripture is very clear we can revert back and vex our souls as we walk in sin.
ICON says "Mortification of remaining sin and corruption...yes that must happen!!" but Paul says if now we need to see the condition of the word if here:
1st Class = Positive - True
2nd Class = Negative - False
3rd Class = Neutral - Maybe
4th Class = Wish List
So Paul is using it in the Third class maybe we will mortify the deeds of the flesh but maybe we won't too. The term if must be looked at in the class it is used. Here we see Paul saying maybe we through the power of the Spirit mortify the deeds of the flesh, then we shall live operating in the Power of the Spirit.
John in 1 st John 1:9 uses the same class of if, maybe we will confess our sins, it says if we confess our sins, again it is we who must do this.
John also reiterates that a believer can walk in sin notice 1 John 1:6 If we say that we have fellowship with him, and walk in darkness, we lie, and do not the truth:
Again Maybe some will say I have fellowship with Christ but the are walking in sin they lie and are not doing the truth, again the key word here is "we" John is speaking to believers.
Then he completes it with these verses:
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.
8 If we say that we have no sin, we deceive ourselves, and the truth is not in us.
9 If we confess our sins, he is faithful and just to forgive us our sins, and to cleanse us from all unrighteousness.
10 If we say that we have not sinned, we make him a liar, and his word is not in us.
It is filled with the 3 rd class condition of "IF". Througout scripture the Apostles make it clear a believer can walk in darkness, walk in sin and not confess it and still be saved a believer can be in the sarx (flesh) be a Sarkikos (carnal) person and yet still be saved.