Again, this is only a way of speaking. There will be no redemption of anyone's physical body due to the fact that "the flesh counts for nothing", and the gospel narratives themselves indicate that the risen Christ is not a physical body, but a spiritual presence, e.g. "where two or three are gathered in my name, I will be there in the midst"; "what you do to the least of my brethren you do to me": "not me, but Christ in me". It is not the physical body that produces fruit, but the spirit dwelling within.
Your body dies, but if you believe you are the body that sins, then you will die in those sins. Paul points out that there is nothing that can separate one from Christ, but if one already views themselves as separated, well then they haven't gotten to the starting line yet. After Adam's fall, he saw himself as separated, evidently you still do as well.
Explain why Paul said that he can become a castaway.
1 Corinthians 9:24 Know ye not that they which run in a race run all, but one receiveth the prize? So run, that ye may obtain. 25 And every man that striveth for the mastery is temperate in all things. Now they do it to obtain a corruptible crown; but we an incorruptible. 26 I therefore so run, not as uncertainly; so fight I, not as one that beateth the air: 27 But I keep under my body, and bring it into subjection: lest that by any means, when I have preached to others, I myself should be a castaway.
Explain why the Father would bother to chasten those who did not strive against sin if we could never sin.
Hebrews 12:1Wherefore seeing we also are compassed about with so great a cloud of witnesses, let us lay aside every weight, and the sin which doth so easily beset us, and let us run with patience the race that is set before us, 2 Looking unto Jesus the author and finisher of our faith; who for the joy that was set before him endured the cross, despising the shame, and is set down at the right hand of the throne of God. 3 For consider him that endured such contradiction of sinners against himself, lest ye be wearied and faint in your minds. 4 Ye have not yet resisted unto blood, striving against sin. 5 And ye have forgotten the exhortation which speaketh unto you as unto children, My son, despise not thou the chastening of the Lord, nor faint when thou art rebuked of him: 6 For whom the Lord loveth he chasteneth, and scourgeth every son whom he receiveth. 7 If ye endure chastening, God dealeth with you as with sons; for what son is he whom the father chasteneth not? 8 But if ye be without chastisement, whereof all are partakers, then are ye bastards, and not sons. 9 Furthermore we have had fathers of our flesh which corrected us, and we gave them reverence: shall we not much rather be in subjection unto the Father of spirits, and live? 10 For they verily for a few days chastened us after their own pleasure; but he for our profit, that we might be partakers of his holiness. 11 Now no chastening for the present seemeth to be joyous, but grievous: nevertheless afterward it yieldeth the peaceable fruit of righteousness unto them which are exercised thereby.
I believe this also applies to why saved believers are left behind for not abiding in Him when the Bridegroom comes.
Revelation 2:18 And unto the angel of the church in Thyatira write; These things saith the Son of God, who hath his eyes like unto a flame of fire, and his feet are like fine brass; 19 I know thy works, and charity, and service, and faith, and thy patience, and thy works; and the last to be more than the first. 20 Notwithstanding I have a few things against thee, because thou sufferest that woman Jezebel, which calleth herself a prophetess, to teach and to seduce my servants to commit fornication, and to eat things sacrificed unto idols. 21 And I gave her space to repent of her fornication; and she repented not. 22 Behold, I will cast her into a bed, and them that commit adultery with her into great tribulation, except they repent of their deeds. 23 And I will kill her children with death; and all the churches shall know that I am he which searcheth the reins and hearts: and I will give unto every one of you according to your works. 24 But unto you I say, and unto the rest in Thyatira, as many as have not this doctrine, and which have not known the depths of Satan, as they speak; I will put upon you none other burden.
Not to mention the daily prayer to the Father the Lord taught us to forgive us of our trespasses or our debts; hence our sins.
Anyone who thinks that they can still continue to sin while Christ remains within them isn't paying attention. Moreover, try this little experiment sometime. The next time you're driving down the freeway, and a highway patrol or state trooper gets into your rear view mirror, consider how difficult it is for you to speed up, or change lanes without using your turn signal, etc. This is a great way to get honest with oneself, and see that unless or until one becomes aware of the presence of Christ within them, they will most assuredly continue to sin for the rest of their lives. That's the Old Covenant. Those who get that new heart, can't sin. The new creation isn't created with that ability.
Well, there are believers who are foolish that do not know any better that are sowing to the flesh and then there are fiery trials that believers finds himself going to Jesus in prayer for help.
Yes, John is contrasting the two ways of living, i.e. continuing to rely upon Christ's sacrifice to cover the sins of those who are still under the Old Covenant, versus those who are a new creation in Christ. You appear to be conflating the two. There is no New Covenant in your theory because if it's no better than the Old, then it is the new in name only.
No. John is addressing believers who thinks sin is no longer sin when they do it for why he points out that they are sinning and need Jesus Christ to forgive them of their sins and for His help to no longer walk in then or in darkness.
And yet Christ pointed out that people were making their way into the kingdom over 2000 years ago. When John asked, he pointed out that the blind see, the deaf hear, and the dumb speak. They didn't have to wait, but evidently, you're not seeking quite a much as they were. They weren't messing around and waiting for an engraved invitation. You don't get your wedding clothes clean by continuing to sin.
I agree if a believer was intentionally using Jesus Christ as hell insurance to continue to live in sin willfully. They run the risk of being left behind, disqualified from being partakers of the firstfruits of the resurrection at the rapture event and not just reaping corruptions & being overcome.
Galatians 6:7 Be not deceived; God is not mocked: for whatsoever a man soweth, that shall he also reap. 8 For he that soweth to his flesh shall of the flesh reap corruption; but he that soweth to the Spirit shall of the Spirit reap life everlasting. 9 And let us not be weary in well doing: for in due season we shall reap, if we faint not. 10 As we have therefore opportunity, let us do good unto all men, especially unto them who are of the household of faith.
2 Peter 2:18 For when they speak great swelling words of vanity, they allure through the lusts of the flesh, through much wantonness, those that were clean escaped from them who live in error. 19 While they promise them liberty, they themselves are the servants of corruption: for of whom a man is overcome, of the same is he brought in bondage. 20 For if after they have escaped the pollutions of the world through the knowledge of the Lord and Saviour Jesus Christ, they are again entangled therein, and overcome, the latter end is worse with them than the beginning. 21 For it had been better for them not to have known the way of righteousness, than, after they have known it, to turn from the holy commandment delivered unto them. 22 But it is happened unto them according to the true proverb, The dog is turned to his own vomit again; and the sow that was washed to her wallowing in the mire.
So what you build on that foundation depends on how we are being received by Him as a vessel unto honor to attend the Marriage Supper in Heaven or disqualified in being damned as vessels unto dishonor to die left behind, to be with the Lord in spirit, awaiting their resurrection after the great tribulation.