Paul says that the gentiles who keep the "requirements of the law" (circumcision); will his uncircumcision not be regarded as circumcision? How shall the gentiles be "regarded" as being circumcised without actually becoming circumcised? There is certainly a benefit in being circumcised because they have the ACTUAL WORDS OF GOD! Please do not misunderstand Paul's words, remember his words are hard to understand. Paul is a pharisee, he keeps and preaches the law of circumcision on the 8th day.
For Jews yes - but not for gentiles
See Acts 20: 20 And when they heard
about them, they
began glorifying God; and they said to him, “You see, brother, how many thousands there are
among the Jews of those who have believed, and they are all zealous for the Law; 21 and they have been told about you, that you are
teaching all the Jews who are among the Gentiles to abandon Moses, telling them not to circumcise their children nor to walk according to the customs. 22 So what is
to be done? They will certainly hear that you have come. 23 Therefore, do as we tell you: we have four men who have a vow upon themselves; 24 take them along and purify yourself together with them, and pay their expenses so that they may shave their heads; and
then everyone will know that there is nothing to what they have been told about you, but that you yourself also conform, keeping the Law. 25
But regarding the Gentiles who have believed, we sent a letter, having decided that they should abstain from meat sacrificed to idols and from blood and what is strangled, and from sexual immorality.”
Clearly they were keeping the division between Jews and gentiles regarding circumcision. They don't accuse Paul of telling gentiles not to be circumcised because they themselves did not think there was such a requirement for gentiles.
In Acts 13, and Acts 17 and Acts 18 these gentiles worship with Jews in synagogues but are not required to be circumcised even by the non-Christian Jews... because there was no such OT command for gentiles.
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Acts 21
27 When the seven days were almost over, the Jews from Asia, upon
seeing him in the temple, began to stir up all the crowd and laid hands on him, 28 crying out, “Men of Israel, help! This is the man who instructs everyone everywhere against our people and the Law and this place; and besides,
he has even brought Greeks into the temple and has defiled this holy place!” 29 For they had previously seen Trophimus the Ephesian in the city with him, and they thought that Paul had brought him into the temple
The same Christian gentiles - allowed in the synagogues - not allowed in the temple because they are not circumcised.