In Thailand, a culture characterised by social interdependence, community-focused teamwork in reaching people for Christ is a vital key. In developing sustainability, it is essential to seek ways to mitigate potential disruptions to the team's effectiveness created by new team members. This qualitative autoethnographic study aims to uncover factors shaping an individual’s ‘self-construal’ or self-perception in relation to others in a group. My unique vantage point for this study is the lived experiences as a ‘missionary kid’, ‘first term missionary’, ‘third culture kid’, and the past three decades as a ‘career missionary’ in multiethnic teamwork reaching Thai society. The phenomena will be researched using the following methods: retrospective autoethnography of my own experience, interviews and open-ended surveys with peers, and systematic searches into pre-existing documents of my missionary parents. The descriptive data extracted from the complex layers of thoughts, emotions, and behaviours will reveal repetitive patterns, symbols, and codes for interpretation and analysis using relevant theories outlined in the literature review. The end product will engage the reader evocatively and analytically in gleaning new knowledge for developing sustainable teamwork that reaches the hearts of the Thais in their society.