Reconstructing the Doctrine of the Church amid Digital Transformation: A Systematic-Theological Approach to Esse Ecclesiae and Forma Ecclesiae

Digital transformation raises a doctrinal question: how should the church understand its identity, communion, embodied life, sacraments, and mission when its practices are mediated by digital technologies? This article develops a systematic-theological framework for evaluating digital ecclesial practices by bringing selected biblical texts into dialogue with classical ecclesiology and recent research on digital church. Through critical library research, contextual biblical interpretation, and comparative doctrinal analysis, it argues that digital technologies may reshape the forma ecclesiae but cannot independently determine the esse ecclesiae. The article's distinctive contribution is to operationalize this distinction through five interrelated criteria- Christological, pneumatological, communal, sacramental-liturgical, and missional-ethical- and to show how they can diagnose concrete digital practices rather than merely describe technological change. These criteria are applied to livestreamed worship, online participation and pastoral interaction, sacramental questions, and digital accessibility. The framework neither rejects digital mediation in advance nor treats connectivity as equivalent to ecclesial communion; instead, it provides a theological basis for discerning when changing forms serve, strain, or contradict the church's confessed identity and mission.