In addition, Zizioulas also was a visiting professor at the Research Institute in Systematic Theology of King's College London.

In the same year, he assumed a full-time academic post at Thessaloniki University's School of Theology as professor of dogmatics.

The theology of Metropolitan John reflects the influence of Russian émigré theologians such as Nikolai Afanassieff, Vladimir Lossky and his teacher Georges Florovsky.

Zizioulas has also been significantly influenced by the ascetical theology of Archimandrite Sophrony (Sakharov),[10] founder of the Stavropegic Monastery of St John the Baptist in Essex, England.

Zizioulas' ecclesiology was first developed in his doctoral dissertation, subsequently published in English as Eucharist, Bishop, Church.

[citation needed] He argues that full humanity is achieved only as person so that they may participate (koinonia) in the Trinitarian life of God.

He makes use of existentialist philosophers and novelists, notably the French absurdist writer Albert Camus, to show that the only type of ontological freedom in the biological hypostasis is the choice to commit suicide.