It's hard to respond to this because you and I are reading these passages differently. But yes, the council would've agreed with Paul's message in Galatians 5 regarding fleshy circumcision because that's why James pronounced his instructions be sent to all new Gentile converts. Fleshy circumcision wasn't necessary because the true form of circumcision is of the heart, by the Spirit.
Circumcision of the Heart Defined
Deuteronomy 10:12-17
12 And now, Israel, what doth the Lord thy God require of thee, but to fear the Lord thy God, to walk in all his ways, and to love him, and to serve the Lord thy God with all thy heart and with all thy soul
13 To keep the commandments of the Lord, and his statutes, which I command thee this day for thy good?
14 Behold, the heaven and the heaven of heavens is the Lord's thy God, the earth also, with all that therein is.
15 Only the Lord had a delight in thy fathers to love them, and he chose their seed after them, even you above all people, as it is this day.
16 Circumcise therefore the foreskin of your heart, and be no more stiffnecked.
17 For the Lord your God is God of gods, and Lord of lords, a great God, a mighty, and a terrible, which regardeth not persons, nor taketh reward:
Circumcision of the heart is to fear the Almighty, walk in all His ways, love Him, and serve Him with all one's heart and soul and to keep His commandments...this is why flesh circumcision isn't necessary, because it's just an outward expression of the true circumcision that happens when someone loves the living God so much to want to serve him with everything they are.
Fleshy circumcision is going backward because, after the giving of the Holy Spirit, true circumcision (i.e. love & obedience) is now possible in fulfillment of the New Covenant promised in Jeremiah 31:33.
Jeremiah 31:33 (partial)
I will put my law in their minds and write it on their hearts
Ezekiel 36:27
And I will put my Spirit in you and move you to follow my decrees and be careful to keep my laws.
A spiritually circumcised person WANTS to obey the living God; wants to follow His commandments.
So the council said to new gentile converts, "don't worry about fleshy circumcision, but do this for now; avoid these sins..."
- pollution of idols
- fornication
- things strangled
- from blood
...because "Moses" (i.e., God's law delivered through Moses) is preached to them every sabbath day in the synagogues.
In other words, they'll eventually learn everything that is required for obedience in time, but for now, tell them to stay away from the four sins above, which would be a significant departure from their past lives as pagans.
Circumcision of the Heart Defined
Deuteronomy 10:12-17
12 And now, Israel, what doth the Lord thy God require of thee, but to fear the Lord thy God, to walk in all his ways, and to love him, and to serve the Lord thy God with all thy heart and with all thy soul
13 To keep the commandments of the Lord, and his statutes, which I command thee this day for thy good?
14 Behold, the heaven and the heaven of heavens is the Lord's thy God, the earth also, with all that therein is.
15 Only the Lord had a delight in thy fathers to love them, and he chose their seed after them, even you above all people, as it is this day.
16 Circumcise therefore the foreskin of your heart, and be no more stiffnecked.
17 For the Lord your God is God of gods, and Lord of lords, a great God, a mighty, and a terrible, which regardeth not persons, nor taketh reward:
Circumcision of the heart is to fear the Almighty, walk in all His ways, love Him, and serve Him with all one's heart and soul and to keep His commandments...this is why flesh circumcision isn't necessary, because it's just an outward expression of the true circumcision that happens when someone loves the living God so much to want to serve him with everything they are.
Fleshy circumcision is going backward because, after the giving of the Holy Spirit, true circumcision (i.e. love & obedience) is now possible in fulfillment of the New Covenant promised in Jeremiah 31:33.
Jeremiah 31:33 (partial)
I will put my law in their minds and write it on their hearts
Ezekiel 36:27
And I will put my Spirit in you and move you to follow my decrees and be careful to keep my laws.
A spiritually circumcised person WANTS to obey the living God; wants to follow His commandments.
So the council said to new gentile converts, "don't worry about fleshy circumcision, but do this for now; avoid these sins..."
- pollution of idols
- fornication
- things strangled
- from blood
...because "Moses" (i.e., God's law delivered through Moses) is preached to them every sabbath day in the synagogues.
In other words, they'll eventually learn everything that is required for obedience in time, but for now, tell them to stay away from the four sins above, which would be a significant departure from their past lives as pagans.
But that we write unto them, that they abstain from pollutions of idols, and from fornication, and from things strangled, and from blood.
Strong's Greek: 235. ἀλλά (alla) -- otherwise, on the other hand, but (biblehub.com)
HELPS Word-studies
235 allá (typically a strong adversative conjunction) – but (but instead), nevertheless, on the contrary. 235 (allá), the neuter plural of 243 /állos ("other"), literally means "otherwise" or "on the other hand" (Abbott-Smith).
Basically "rather than". Not sure if this helps very much. But it is illustrative of the essentially "contrary/negative" verdict.
I take it therefore that verse 21 carries with it the notion that the gentiles were well aware of Jewish law as regards morality, decency, and a righteous pattern of life. So demanding of gentiles a strict to the letter ritual law-keeping was uncalled for given the circumstances.