The abstract term for those who are circumcised. In the Old Testament, circumcision was a metaphor for purity. See Lev 26:41; Deu 10:16; Deu 30:6; Eze 44:7, etc.
Worship God in the spirit (πνεύματι Θεῷ λατρεύοντες)
The correct reading is θεοῦ of God. Render, as Rev., worship by the Spirit of God. Worship. See on Rev 22:3. Paul uses the Jews' word which denoted their own service of Jehovah as His peculiar people. Compare Act 26:7. A Jew would be scandalized by the application of this term to Christian worship.
Rejoice in Christ Jesus (καυχώμενοι)
Rev., better, glory. Compare Jer 9:23, Jer 9:24, and 1Co 1:31; 2Co 10:17.