The Orthodox liturgy is a religious phenomenon that can be analyzed phenomenologically and theologically alike, given the emphasis that both phenomenology and Orthodox theology place on experience. By proposing the Kingdom of God instead of the natural world without being able to annihilate the latter in the name of the former, the liturgy seeks divine-human communion. Through the dialogue of prayer, through symbolic and iconic openings, as well as through apophatic theology, the liturgy emphasizes the horizon of mystery as a horizon essential to the way man positions himself before God. The present text attempts to demonstrate that apophaticism, understood as an experience of the mysterious presence of God, is one of the crucial dimensions of the Orthodox liturgy; and that this apophatic presence of God reveals a way of thinking which does not become onto-theology, not even when using concepts borrowed from metaphysics. The overcoming of onto-theology is achieved here not by abandoning concepts such as “being” and “cause” but by placing the language game in the field of prayer and apophatic theology.