For Zizioulas, eschatology is not simply a doctrine; it is an orientation, a perspective, a mode of existence. Eschatology does not concern only the future; it affects our past as well as our present. This is how the Church viewed and experienced the “last things” from the beginning.

Ever since the eminent Biblical theologian Johannes Weiss and then the great Albert Schweitzer convincingly advanced the position that the “essence” of the Gospel is to be found in the preaching of the Kingdom of God, eschatology has assumed central importance not only in Biblical but also in Systematic theology. From the last chapter of the Dogmatics, which it usually was, eschatology began to define the whole of Dogmatic theology, both in method and in content. Modern Orthodox dogmatic theology remained essentially unaffected by this development. In his studies, relying mainly on the Eucharistic experience and theology of the Orthodox Church but also on Fathers of the Church, such as Maximus the Confessor, Zizioulas attempts to restore and project the eschatological dimension to the center of theological thought. The whole orientation of theology is eschatological and, therefore, fundamentally Biblical. The relationship between history and eschatology is organic, but eschatology should not be considered either as the conclusion of a dynamic of historical becoming in an Aristotelian sense (teleological—cf. the ideas of Teilhard de Chardin) or as a return to the original ideal situation in a Platonic manner (e.g., Origen and Augustine). It is instead a dialectical relationship in which the end times “invade” with the presence of Christ in history without turning into history. This dialectical relationship is experienced and realized par excellence in the Holy Eucharist (cf. Revelation of John), and it introduces into philosophical language and thought the concept of an “iconological ontology” according to which the ultimate truth of beings is really present in history, but only in the form of the Cross and the “sacramental” presence.

In his major and ultimate book titled Remembering the Future, the late Metropolitan of Pergamon John Zizioulas shows that eschatology can have crucial implications for ontology, i.e., for being itself. Answering some of the biggest philosophical and theological questions today, Zizioulas shows how this eschatological ontology permeates Christian doctrine, particularly that of creation and ecclesiology. He also points out some important ethical implications.