Note 1 at Acts 11:2: This terminology, "of the circumcision," is always used to distinguish Jews. It refers back to the covenant of circumcision that God made with Abraham in Genesis 9-14, 23-27, and with all his seed. The term became synonymous with Jews in general and was used to distinguish the nation of Israel (Rom. 2:25-26; 3:30; 4:9; Gal. 2:9).

In this instance, "of the circumcision" is referring to Jewish Christians. These people were born again but they had not yet received the revelation that Christianity was different than Judaism and that a man did not have to be circumcised to be saved.