The method of arrival is important because we can only be in one of two states. If in the spirit, we will be having the fruits of the spirit, if in the flesh, we will be having the fruits of the flesh. So while being drunken, we could for example be less fighty and murderous (two of the prohibited actions) but we will still end up hurting people in other ways.
A fuller quote from the Galatians letter reads:
But I say, walk by spirit, and you will certainly not fulfill the desire of flesh. For flesh desires against spirit, and spirit against flesh; and these are contrary to one another, that you might not do the things that you desire. But if you are led by the spirit, you are not under the law. Now the deeds of the flesh are obvious, which are: adultery, ...
While that only says that we might not do the things we desire (i.e. not hurting others) it's expanded in the letter to the Romans 8.1-9:
There is therefore now no condemnation to those who are in Christ Jesus, not according to flesh walking, but according to spirit. For the law of the spirit of life in Christ Jesus made me free from the law of sin and of death. For what the law couldn’t do, in that it was weak through the flesh, God did, sending his own son in the likeness of sinful flesh and for sin, he condemned sin in the flesh; that the ordinance of the law might be fulfilled in us, who walk not according to flesh, but according to spirit. For those being according to flesh mind the things of the flesh, but those according to spirit, the things of the spirit. For the mind of the flesh is death, but the mind of the spirit is life and peace; because the mind of the flesh is hostile toward God; for it is not subject to God’s law, neither indeed can it be. Those who are in the flesh can’t please God. But you are not in flesh but in spirit, if it is so that the spirit of God dwells in you. But if any man doesn’t have the spirit of Christ, he is not his.
Jesus also described this dichotomy in, for example, Matthew 7.15-20, 12.33 and 13.1-33. (This is not to say that a person can be perfect, nor are these passages saying this given technicalities of their Greek verbs.)
If a psychedelic experience leads to humility, repentance, and love, how do you know it was “of the flesh”? Could it not be a moment when the Spirit spoke through the weakness of flesh, as God does often in scripture?
If God can use a burning bush, a talking donkey, and a dream given to Pharaoh (a pagan king), is it really theologically sound to say that God cannot or will not speak through a psilocybin vision?
Is it possible that your framework is set up to reject any experience you disapprove of, no matter the outcome?
Yes, the account of Balaam's talking donkey is a great illustration that God can and does speak to us when we are going against him. That's also been my experience, and I'm thankful for his patience.
A fuller quote from the Galatians letter reads: But I say, walk by spirit, and you will certainly not fulfill the desire of flesh. For flesh desires against spirit, and spirit against flesh; and these are contrary to one another, that you might not do the things that you desire. But if you are led by the spirit, you are not under the law. Now the deeds of the flesh are obvious, which are: adultery, ...
While that only says that we might not do the things we desire (i.e. not hurting others) it's expanded in the letter to the Romans 8.1-9:
There is therefore now no condemnation to those who are in Christ Jesus, not according to flesh walking, but according to spirit. For the law of the spirit of life in Christ Jesus made me free from the law of sin and of death. For what the law couldn’t do, in that it was weak through the flesh, God did, sending his own son in the likeness of sinful flesh and for sin, he condemned sin in the flesh; that the ordinance of the law might be fulfilled in us, who walk not according to flesh, but according to spirit. For those being according to flesh mind the things of the flesh, but those according to spirit, the things of the spirit. For the mind of the flesh is death, but the mind of the spirit is life and peace; because the mind of the flesh is hostile toward God; for it is not subject to God’s law, neither indeed can it be. Those who are in the flesh can’t please God. But you are not in flesh but in spirit, if it is so that the spirit of God dwells in you. But if any man doesn’t have the spirit of Christ, he is not his.
Jesus also described this dichotomy in, for example, Matthew 7.15-20, 12.33 and 13.1-33. (This is not to say that a person can be perfect, nor are these passages saying this given technicalities of their Greek verbs.)