This dissertation explores Paul's social relationships and identities as an itinerant diaspora figure with localized communities of Christ-believers by applying some tools and insights from diaspora studies. The focus of this study is on three specific issues: (1) Paul's interactions with other Diaspora Jews, especially in the Galatians 2 incident (11-14), (2) Paul's relationship with the nations, specifically his dealings with the Galatians, and (3) Paul's collection project (mentioned in Gal 2:10, 1 Cor 16:1-4, 2 Cor 8-9, Rom 15:25-28). These specific issues serve to illustrate Paul's diasporic identities and social relations in his movements across boundaries. Paul's diaspora existence becomes sharper through the analysis of the concepts of diaspora space, relational space, `home,' ancestral `homeland,' and performance of identities. This dissertation shows the necessity of studying Paul's diaspora politics--that is the organization and messiness of social relationships--within the complexities of first century Diaspora Judaism. The diasporic space Paul occupies is very important to consider in order to understand the ways in which the apostle to the nations struggled between theological ideals and negotiating social realities with different social actors of the early Jesus movement.