Are you agreeing with Cooper that the devil created Judaism?
In context;
Romans 8:1There is therefore now no condemnation to them which are in Christ Jesus, who walk not after the flesh, but after the Spirit. 2 For the law of the Spirit of life in Christ Jesus hath made me free from the law of sin and death.
So that means those in Christ Jesus who do walk after the flesh, there will be condemnation as they will be held accountable since Christ had set us free from the law of sin & death.
3 For what the law could not do, in that it was weak through the flesh, God sending his own Son in the likeness of sinful flesh, and for sin, condemned sin in the flesh:4 That the righteousness of the law might be fulfilled in us, who walk not after the flesh, but after the Spirit.
Underlined word "might be" as sating now that we have been set free, we are not to walk after the flesh but after the Spirit.
5 For they that are after the flesh do mind the things of the flesh; but they that are after the Spirit the things of the Spirit. 6 For to be carnally minded is death; but to be spiritually minded is life and peace. 7 Because the carnal mind is enmity against God: for it is not subject to the law of God, neither indeed can be. 8 So then they that are in the flesh cannot please God.
There you go. Proof above that saved believers that mind the things of the flesh cannot please God.
9 But ye are not in the flesh, but in the Spirit, if so be that the Spirit of God dwell in you. Now if any man have not the Spirit of Christ, he is none of his.
This is signifying the difference between a believer and an unbeliever for why believers are being exhorted not to live after the fesh that Jesus has set us free from.
10 And if Christ be in you, the body is dead because of sin; but the Spirit is life because of righteousness. 11 But if the Spirit of him that raised up Jesus from the dead dwell in you, he that raised up Christ from the dead shall also quicken your mortal bodies by his Spirit that dwelleth in you.
This is not doubting the believer is saved, but exhorting why sin has no dominion over our lives any more unless we let it by living after the flesh.
If you doubt this to be true then pay attention to the next verse.
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.
That is Paul testifying to the consequence to believers if they live after the flesh. If that could never happen to a saved believer, then there would be no need to say that.
No. 1 John 3:8 is testifying to what Jesus Christ can do for us, to destroy the works of the devil in our lives so sin has no more dominion over us.
1 John 3:3 And every man that hath this hope in him purifieth himself, even as he is pure.... 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.
You just need His help to keep applying your hope in Him daily that He will lead you away from temptation, and deliver you from the evil one.