The Dutch Reformed Church (DRC) in South Africa faces challenges due to rapid demographic shifts that reduce the proportion of traditional Afrikaner members and threaten the financial viability of its ministries. Historically, the DRC has relied on geographical congregational boundaries to define membership. However, recent policies have shifted towards individual choice and non-geographical affiliations. This study investigates whether rediscovering congregational boundaries can empower the DRC to fulfil its missional calling in a diversifying South Africa, emphasizing parochial ecclesiology grounded in the Word and Sacrament. Employing autoethnography, this research integrates personal reflections from the author’s experience as a student minister with theological analysis, drawing on postfoundational practical theology, missional theology and confessional writings. The study finds that the DRC’s move away from geographical boundaries prioritizes individual choice over communal responsibility. A parochial approach, emphasizing local congregations as sacred spaces for all within a defined area, could realign the DRC with its missional identity by reimagining church buildings as central to sacramental ministry and welcoming diverse populations as neighbours. Re-embracing geographical boundaries presents a pathway for the DRC to fulfil its missional calling by fostering inclusive sacramental communities and challenging the church to address historical divisions and pursue practical sacramental unity. Future studies should investigate how such a model can be effectively implemented in South Africa’s complex sociohistorical context.