In this paper, I explore Paul’s use of πολίτευμα in light of Greco–Roman Imperial context and its implication for social identity formation in Phil 3:20–21. Based on my analysis of the semantic range of πολίτευμα and the way πολίτευμα used in the Greco-Roman and Jewish contexts, I argue that the term πολίτευμα is primarily associated with three components, namely geographical space, ruling class (governing body) and citizen body. In addition, I contend that πολίτευμα is related to social identity formation with respect to the three categories of cognitive, emotional, and evaluative dimensions in the context of Phil 3:17–21. Then, I conclude that by using the term πολίτευμα in relation to σωτήρ and κύριος in 3:20, Paul intends to encourage that the Philippian believers’ action must be practiced based on a Christological paradigm mentioned in 2:6–11, by considering Jesus as their Saviour and Lord, heavens as their new space, and the new identity as the people of God to live under Roman-Colony Philippi.
Keywords: Citizen, governing, social identity formation, imperial context