A child of God does not practice sin, is a new creature, but is not sinless. If this state were possible in the flesh, for those other than our Lord Jesus, there'd have been no need for His atonement work, to satisfy the justice required of our Holy God:
The second part is how he connects the first part as necessitating the second part. It is a false syllogism.
Jesus did not die to satisfy a "justice requirement" like these people believe. That doctrine was invented by a man called Anselm in the 11th Century. Here is a little history...
The satisfaction view of the atonement is a theory in Christian theology about the meaning and effect of the death of Jesus Christ and has been traditionally taught in Western Christianity, specifically in the Roman Catholic, Lutheran, and Reformed circles. Theologically and historically, the word "satisfaction" does not mean gratification as in common usage, but rather "to make restitution": mending what has been broken, paying back what was taken. Since one of God's characteristics is justice, affronts to that justice must be atoned for.[SUP][1][/SUP] It is thus connected with the legal concept of balancing out an injustice. Drawing primarily from the works of Anselm of Canterbury, the satisfaction theory teaches that Christ suffered as a substitute on behalf of humankind satisfying the demands of God's honor by his infinite merit. Anselm regarded his satisfaction view of the atonement as a distinct improvement over the older ransom theory of the atonement, which he saw as inadequate. Anselm's theory was a precursor to the refinements of Thomas Aquinas and John Calvin which introduced the idea of punishment to meet the demands of divine justice.
The Bible does not teach any such thing about the death of Christ. Rather the Bible teaches...
Tit 2:14 Who gave himself for us, that he might redeem us from all iniquity, and purify unto himself a peculiar people, zealous of good works.
Jesus died to redeem us from all iniquity and make us pure. Jesus did not die to satisfy justice. If justice were to be satisfied then God would send us all to hell. In lieu of that God offers mercy upon those who will return to favour by the means of Jesus Christ. The word redeem means "to set free from bondage by payment of a ransom." Jesus BOUGHT US unto Himself. We had all sold ourselves into condemnation through sinning and aligned ourselves with Satan's kingdom, Jesus purchases us from Satan's kingdom via being our kinsman who offers to redeem the inheritance of the bride through marriage.
Jesus obeyed God unto death and obtained an inheritance. Jesus did what all other men have failed to do.
Heb 1:4 Being made so much better than the angels, as he hath by inheritance obtained a more excellent name than they.
Judgement was handed over to Christ and we have the opportunities to inherit salvation through Him.
Heb 1:14 Are they not all ministering spirits, sent forth to minister for them who shall be heirs of salvation?
Jesus overcame the world and tasted death for all men...
Heb 2:9 But we see Jesus, who was made a little lower than the angels for the suffering of death, crowned with glory and honour; that he by the grace of God should taste death for every man.
And we are sanctified or set apart from all evil THROUGH Jesus when we suffer WITH Him...
Heb 2:10 For it became him, for whom are all things, and by whom are all things, in bringing many sons unto glory, to make the captain of their salvation perfect through sufferings.
Heb 2:11 For both he that sanctifieth and they who are sanctified are all of one: for which cause he is not ashamed to call them brethren,
1Pe 4:1 Forasmuch then as Christ hath suffered for us in the flesh, arm yourselves likewise with the same mind: for he that hath suffered in the flesh hath ceased from sin;
1Pe 4:2 That he no longer should live the rest of his time in the flesh to the lusts of men, but to the will of God.
Jesus showed us the way, the way to be set free from sin. We are begotten THROUGH Him via the new birth unto obedience (ie. we walk according to the will fo God)...
1Pe 1:2 Elect according to the foreknowledge of God the Father, through sanctification of the Spirit, unto obedience and sprinkling of the blood of Jesus Christ: Grace unto you, and peace, be multiplied.
1Pe 1:3 Blessed be the God and Father of our Lord Jesus Christ, which according to his abundant mercy hath begotten us again unto a lively hope by the resurrection of Jesus Christ from the dead,
1Pe 1:4 To an inheritance incorruptible, and undefiled, and that fadeth not away, reserved in heaven for you,
1Pe 1:5 Who are kept by the power of God through faith unto salvation ready to be revealed in the last time.
...with pure hearts having been born again through submitting ourselves to the power of God in which we are raised up...
1Pe 1:22 Seeing ye have purified your souls in obeying the truth through the Spirit unto unfeigned love of the brethren, see that ye love one another with a pure heart fervently:
1Pe 1:23 Being born again, not of corruptible seed, but of incorruptible, by the word of God, which liveth and abideth for ever.
...and very importantly, we are ENJOINED INTO COVENANT with God by the blood...
Heb 9:15 And for this cause he is the mediator of the new testament, that by means of death, for the redemption of the transgressions that were under the first testament, they which are called might receive the promise of eternal inheritance.
Heb 9:16 For where a testament is, there must also of necessity be the death of the testator.
Heb 9:17 For a testament is of force after men are dead: otherwise it is of no strength at all while the testator liveth.
Heb 9:18 Whereupon neither the first testament was dedicated without blood.
Heb 9:19 For when Moses had spoken every precept to all the people according to the law, he took the blood of calves and of goats, with water, and scarlet wool, and hyssop, and sprinkled both the book, and all the people,
Heb 9:20 Saying, This is the blood of the testament which God hath enjoined unto you.
The death of Christ has NOTHING to do with satisfying justice like people think. It has everything to do with providing a means by which a rebellious people can be reconciled to God IF they forsake their rebellion.
So going back to the fallacy. People believe that the death of Christ serves the purpose of COVERING OVER the ONGOING SINFULNESS wrought by people being entrapped in a FLESH BODY. Nothing could be further from the truth.
So when a statement like this is made...
we can't wash ourselves clean in this flesh, period, by any means.
Isa 1:16 Wash you, make you clean; put away the evil of your doings from before mine eyes; cease to do evil;
Isa 1:17 Learn to do well; seek judgment, relieve the oppressed, judge the fatherless, plead for the widow.
Isa 1:18 Come now, and let us reason together, saith the LORD: though your sins be as scarlet, they shall be as white as snow; though they be red like crimson, they shall be as wool.
Isa 1:19 If ye be willing and obedient, ye shall eat the good of the land:
and
Jas 4:8 Draw nigh to God, and he will draw nigh to you. Cleanse your hands, ye sinners; and purify your hearts, ye double minded.
It is in so doing that we can do this...
Heb 10:22 Let us draw near with a true heart in full assurance of faith, having our hearts sprinkled from an evil conscience, and our bodies washed with pure water.
...in which our PAST SINS and GUILTY CONSCIENCE is WASHED AWAY.
This belief that the "flesh itself is sinful" handicaps people from ever cleansing their hearts because they are deceived into believing that they CANNOT DO IT. If Satan can convince you that you cannot cleanse yourself of wickedness through repentance and faith then you will never do what you perceive as impossible and in doing that the kingdom of God is SHUT to you. This is why Jesus called the Pharisees vipers, because not only would they not approach God in the right manner, they prevented others from doing so, JUST LIKE YOUR PASTORS AND RELIGIOUS TEACHERS TODAY.
We move on...
I defy one of you to say you've not had a hateful or lustful thought, even many times, since being saved; actually, have any complete control over your thoughts now, which our Lord stated are the same as murder or adultery, for instance.
Jesus said...
Mat 5:8 Blessed are the pure in heart: for they shall see God.
Yet people cry, "NO, IT IS IMPOSSIBLE, NONE CAN BE PURE."
Jesus spoke of inward purity on the Sermon on the Mount and how it is necessary in order to enter the kingdom and people cry, "NO WE CANNOT BE PURE, WE ARE ALWAYS SINNING."
Now part of the problem is that people view "mistakes" (ie. doing wrong ignorantly) in the same context as "rebellion" and this error easily serves to reinforce the notion that "none can be pure" because in their mind they associate "purity with sinless perfection." That is why they often oppose those who preach that "sinning stops" with accusations of "sinless perfection." It is pure unreasoned fallacy.
Another aspect is that people view "temptation as equal to sin" when temptation is not sin. Temptation is natural, sin is unnatural. We are to resist temptation and the devil will flee every single time.
The Bible reads...
1Co 10:13 There hath no temptation taken you but such as is common to man: but God is faithful, who will not suffer you to be tempted above that ye are able; but will with the temptation also make a way to escape, that ye may be able to bear it.
Yet if one claims to always take the way of escape they will be accused of lying because the notion of "flesh necessitating sin" opposes it. It is yet another example of religious dogma superseding the plain words of scripture.
And the last bit...
There isn't even enough OT law written, to cover all our sin, which sin is ALL things that fall short of holy, Godly perfection. We will not put on the incorruptible until the first resurrection. Read Romans 7, the predicament of the corruptible flesh very clear, versus walking in faith, in the Spirit, with Christ.
The wretch of Romans 7 is a man convicted in mind, who knows the law, who is addicted to sin. He finds no power through the law to set him free from his wretched state. Paul was teaching that it is through the law (or knowledge of right doing) that sin can kill and that right knowledge (or the law) cannot redeem one from such a dead state. We are set free from the law of sin and death, not via the law, but via the Spirit of life in Jesus Christ. That is why there is no condemnation upon those who are IN Jesus Christ, being in Christ means one is walking according to the Spirit and is no longer sinning unto death. All past sins have been washed away and we walk in purity of heart in a right relationship to God submitted to His will. He chastises us to teach us the right way when we err, but as far as rebellion to God, there is none for we have crucified the old man with Christ in the baptism of repentance and therefore we no longer serve sin, rather we are servants of righteousness.
That is what the Bible teaches. Be like a Berean and dig deep and see if these things are true.