In introducing the fifth chapter of Being as Communion, Metropolitan Zizioulas points out that Orthodoxy is known for its emphasis on both tradition and worship.

On the one hand, Orthodoxy is known for its devotion to tradition. This makes history acquire decisiveness in the consciousness of the Orthodox Churches, which is thus orientated towards the past with respect and devotion. On the other hand, Orthodoxy is known for the centrality and importance which it attributes to worship in its life and theology, and this leads it to a “theophanic” and in a sense “meta-historical” view of the Church. Deep in these two aspects of Orthodox consciousness lie the seeds of a duality which could easily be turned into a dichotomy. (171)

This duality has been present since the beginning of the Church and is also of relevance to other Churches. And it has particular bearing on our understanding of apostolicity and succession which will be further explored in this chapter.