Abstract This article provides a socio-theological study of Molimbu, a local tradition of collective feasting found among the Pamona people in the province of Central Sulawesi in Indonesia. It specifically explores the impact of Molimbu on the Zaitun Dulumai congregation, which is part of the Gereja Kristen Sulawesi Tengah (Central Sulawesi Christian Church, GKST), located in Poso, a city in Central Sulawesi (also known as Celebes), Indonesia. This article explores the manner in which Molimbu contributes to the civil sphere by building harmony within the church. Congregations in this part of Indonesia have been deeply impacted by external Christian values, leadership, and forces that are associated with European missions. But this is not the full story. In the Dulumai congregation, the church is also regulated by the agency of the local tradition called Molimbu. As an ethnic tradition and part of the congregation’s community life, Molimbu becomes a solidarity space connecting every participating individual. The research objective of this article is to describe and analyze Molimbu as a cultural practice that contributes to the civil sphere by building a harmonious congregation at GKST Zaitun Dulumai. The research method used is qualitative and descriptive. The results show that Molimbu contributes significantly to the civil sphere in constructing harmonious Christian congregations by activating sublime values such as equality and respect. Those values foster and nurture harmony within the congregation and are indicated through the traditional Christian concepts of koinonia (fellowship), diakonia (ministry), and maturia (witness).