Well, I'm still not exactly sure what you're asking, but if I were to guess, it would be virtually synonymous with Clare's [paraphrase in post #443] of your question ---- "Do you think you could be born again and do what Hitler did?" ... So, I'll run with that.
In my opinion, I don't believe any born again believer would ever commit the atrocities that Hitler did. I would even take it further and say I don't believe the vast majority of unregenerated people would actually do what Hitler did if given the opportunity [and were not in a state of severe mental decline/disorder].
However, I suppose it's plausible for a born again believer to commit those crimes against humanity if they were suffering from some type of severe cognitive dysfunction. Therefore, only in the case of extreme exceptions like this would a born again believer ever opt to order the deaths of innocent people like Hitler did.
At it's core, the question at hand appears to essentially turn back upon the extent and efficacy of the change of nature that was necessarily accomplished in each person that become a new creature in Christ the moment they were indwelt by the Holy Spirit. [2 Corinthians 5:17, "Therefore if any man be in Christ, he is a new creature: old things are passed away; behold, all things are become new ...
Ezekiel 36:26-27, "I will give you a new heart and put a new spirit in you; I will remove from you your heart of stone and give you a heart of flesh. And I will put my Spirit in you and move you to follow my decrees and be careful to keep my laws."
I would also point out that Paul warned the Ephesians of grieving the Holy Spirit then went on to explicitly why.
“Do not grieve the Holy Spirit of God, by whom you were sealed for the day of redemption. Let all bitterness and wrath and anger and clamor and slander be put away from you, along with all malice. Be kind to one another, tender-hearted, forgiving each other, just as God in Christ also has forgiven you.”
Ephesians 4:30-32 NASB1995
Paul continues in the opening statements of the next chapter.
“Therefore be imitators of God, as beloved children; and walk in love, just as Christ also loved you and gave Himself up for us, an offering and a sacrifice to God as a fragrant aroma. But immorality or any impurity or greed must not even be named among you, as is proper among saints; and there must be no filthiness and silly talk, or coarse jesting, which are not fitting, but rather giving of thanks. For this you know with certainty, that no immoral or impure person or covetous man, who is an idolater, has an inheritance in the kingdom of Christ and God. Let no one deceive you with empty words, for because of these things the wrath of God comes upon the sons of disobedience.”
Ephesians 5:1-6 NASB1995
Do you think Paul told them this because they were incapable of doing these things because they had received a new heart? In 1 Corinthians 2 Paul writes to the Corinthians telling them that unless they set their mind on the Spirit they cannot discern spiritual matters.
“For to us God revealed them through the Spirit; for the Spirit searches all things, even the depths of God. For who among men knows the thoughts of a man except the spirit of the man which is in him? Even so the thoughts of God no one knows except the Spirit of God. Now we have received, not the spirit of the world, but the Spirit who is from God, so that we may know the things freely given to us by God, which things we also speak, not in words taught by human wisdom, but in those taught by the Spirit, combining spiritual thoughts with spiritual words. But a natural man does not accept the things of the Spirit of God, for they are foolishness to him; and he cannot understand them, because they are spiritually appraised. But he who is spiritual appraises all things, yet he himself is appraised by no one. For who has known the mind of the Lord, that he will instruct Him? But we have the mind of Christ.”
1 Corinthians 2:10-16 NASB1995
He continues on this subject into the next chapter
“And I, brethren, could not speak to you as to spiritual men, but as to men of flesh, as to infants in Christ. I gave you milk to drink, not solid food; for you were not yet able to receive it. Indeed, even now you are not yet able, for you are still fleshly. For since there is jealousy and strife among you, are you not fleshly, and are you not walking like mere men?”
1 Corinthians 3:1-3 NASB1995
Again even tho the Corinthians were believers and had received the Holy Spirit they were still carnal and walking like mere men because they weren’t setting their mind on the Spirit.
Paul discusses the same thing in the epistle to the Romans.
“Therefore there is now no condemnation for those who are in Christ Jesus. For the law of the Spirit of life in Christ Jesus has set you free from the law of sin and of death. For what the Law could not do, weak as it was through the flesh, God did: sending His own Son in the likeness of sinful flesh and as an offering for sin, He condemned sin in the flesh, so that the requirement of the Law might be fulfilled in us, who do not walk according to the flesh but according to the Spirit. For those who are according to the flesh set their minds on the things of the flesh, but those who are according to the Spirit, the things of the Spirit. For the mind set on the flesh is death, but the mind set on the Spirit is life and peace, because the mind set on the flesh is hostile toward God; for it does not subject itself to the law of God, for it is not even able to do so, and those who are in the flesh cannot please God. However, you are not in the flesh but in the Spirit, if indeed the Spirit of God dwells in you. But if anyone does not have the Spirit of Christ, he does not belong to Him. If Christ is in you, though the body is dead because of sin, yet the spirit is alive because of righteousness. But if the Spirit of Him who raised Jesus from the dead dwells in you, He who raised Christ Jesus from the dead will also give life to your mortal bodies through His Spirit who dwells in you. So then, brethren, we are under obligation, not to the flesh, to live according to the flesh— for if you are living according to the flesh, you must die; but if by the Spirit you are putting to death the deeds of the body, you will live. For all who are being led by the Spirit of God, these are sons of God.”
Romans 8:1-14 NASB1995
For there is no condemnation for those who ARE IN CHRIST. Not for those who were in Christ at some point.
He condemned sin in the flesh, so that the requirement of the Law might be fulfilled in us, who do not walk according to the flesh but according to the Spirit. Justification is for those who walk in the spirit, not for those who walk in the flesh.
So then, brethren, we are under obligation, not to the flesh, to live according to the flesh for if you are living according to the flesh, you must die; but if by the Spirit you are putting to death the deeds of the body, you will live. For all who are being led by the Spirit of God, these are sons of God. We are under OBLIGATION to walk in the Spirit. IF we walk in the Spirit we will live, if we walk in the flesh we will die.
There are numerous passages that clearly indicate that born again believers who have received the Holy Spirit can in fact ignore the Spirit and fall away leading to condemnation. These are just a few of them.