Providing a metaphysical grounding for liturgical participation, this book argues that “active participation” in the liturgy must be understood principally as our participation in God’s act, particularly in the act of Christ, and only secondarily as our ritual involvement. Utilizing Neoplatonist philosophy, Kjetil Kringlebotten proposes that this should be understood in terms of theurgy, which is the human participation in divine action, which finds its consummation in the incarnation of Christ. Without the incarnation all acts will remain extrinsic and imposed but acts can become real and intrinsic precisely because the incarnation makes possible true union with the divine, a metaphysical union-in-distinction, without confusion, because this union is not extrinsic. Through union with Christ, as the one common focus of the divine-human relation, we can have true union with God and may offer true worship. In order to make sense of active participation, then, we need to understand theology in theurgic terms, where theurgy is understood not as a mechanical “coercion” of God but as a participation in His act, in creation and through Christ as the true theurgist, the “master theurgist,” Whose work transforms our act and the liturgy.