Eastern Orthodox Christians will celebrate Easter this year May 2 in accordance with the Julian calendar.
For many years the East and West have been growing apart rather than closer. What had once been a single church slowly separated into two distinct identities. Many nitpicking differences added heat to the conflict.
The East used Greek as its language; the West used Latin thanks to the Vulgate and Western theologians who wrote in that language.
Forms of worship differed. The bread used in communion, the date of Easter and Lent and how services were conducted differed.
In the Eastern Orthodox church, clergy could marry and were encouraged to; Western priests could not marry. Theologies also differed, the East felt uncomfortable with the West’s doctrine of purgatory. The West used “filioque,” “and from the Son.”
In the Nicene Creed after the clause about the Holy Spirit, which says the Spirit "proceeds from the Father.” To the East, that addition was heretical.
Later centuries saw attempts to reunite the churches, but none were successful. And the short lived “reunion” of 1204 increased the hostility between the two churches. But at the heart of the matter was “power.” But in an age that saw bishop's authority as a key to the stability of the church, no two could claim the same authority.
Subsequently, the East and the West failed to agree and went their separate ways; both churches known for their beautiful services and adding so much to Christianity and the world!