Social workers nowadays are confronted with recurrent issues about religion and spirituality when in contact with diverse client groups. This was also the case in the beginning of the profession around 1900, in Europe as well as in the US. This study analyses the work of a Dutch pioneer in social work, Marie Muller-Lulofs (1854–1954) and presents the religious and worldview aspects of her reflections on social work. Her standard work Van mensch tot mensch (From person to person) of 1916 forms the basic text for theory-driven content analysis by applying the seven-dimension model of worldview of Ninian Smart: doctrine/philosophy, organisations, ethics, stories, experiences, rituals and materials. Results show that Muller-Lulofs makes a strong plea for a secular profession. Social-economic approaches are on the foreground. And yet, the methods, skills and professional attitudes she describes are substantially accounted for in religious and spiritual terms. This is mainly done by introducing narratives and metaphors derived from Christian and Buddhist traditions. It is concluded that Muller-Lulofs uses religion and spirituality in a non-dogmatic and non-prescriptive way, but as a source of inspiration to underpin the new profession. Her approach is relevant for current issues in social work in multicultural societies.