Interpretations of the last book of the New Testament usually dwell upon its visions of things to come. Except for its prayers and hymns, however, little attention has been paid to its liturgical character. This fact is the more surprising since it is just in that respect that the Apocalypse of John differs mostly strikingly from other Jewish and Christian apocalyptic writings. Its visions are presented within a framework of liturgical activities, and toward the end of the book it is hardly possible to dissociate the acts of worship from the visions of the future. This close relationship shows that its liturgical portions are not a purely literary device. Rather in the Seer's mind they form part of the revelatory process itself representing the reaction of initiated creatures to the gradual disclosure of the saving purpose of God and its execution. From the historical viewpoint, this liturgical framework of the Apocalypse of John is interesting, because it contains a number of features which, in a similar manner, occur also in the liturgies of the Ancient Church. Thus it is from the liturgical character of the Apocalypse that the historical development of the Christian liturgy becomes intelligible. Out of the perplexing diversity of its types, the formative principle of its early stages emerges, and a number of motives become visible, some of which have determined its history to the present day. Others, which have no longer a vital role assigned to them, were, nevertheless, preserved on account of the significance originally attached to them. Among these features I mention the ideas of the Eucharistic Parousia, the Church's participation in the angelic worship, the emphasis placed upon the worthiness of the interpreter of Scripture, the connection between the Confession of Sins and the Eucharist, the separation of the believers and unbelievers prior to the heavenly meal, the celebration of the Eucharist as an act of the Church in its cosmic totality, the association of the Eucharist with the Judgment of the World, and the interpretation of the liturgy as a spiritual battle. It will suffice to single out two of these features, which for their lack of centrality in the liturgies are particularly apt to illustrate our point, viz. the participation of the Church in the angelic worship, and the worthiness of the interpreter of Scripture.