This Life of Saint Zayya is provided while keeping in mind the exhortations of Saint John Maximovitch (and also of the ROCOR synod at that time) that Orthodox in the West should recover the “lost” Saints from the pre-Schism era. Further, Orthodox in the West should not fear venerating people from the West who had a cultus before the Great Schism, even if they were never formally canonized or commemorated in the Eastern Church. In the same spirit of recovering our undivided Christian past, I am likewise trying to rediscover the “lost” Saints of the Eastern Lands.

Thus I present to you Saint Zayya, a pre-Schism saint who was born in the year 309 AD and died in the year 431. He is currently venerated only by the Nestorians (the Assyrian Church of the East) – but he lived and died before the Christological controversies that separated the churches. Thus he is a Saint of the Universal Undivided Church. As the Persian Church adopted the Nestorian heresy officially and synodally at the Synod of Beth Lapat in the year 484 AD – officially repudiating the Third Ecumenical Council held at Ephesus in 431 – we have, therefore, Saints in that area till the year 484 AD. And as was already pointed out, Saint Zayya lived and died before the schism of the Persian Church in 484. In fact he even died before the Council of Ephesus was convened, dying on January 7, 431 AD and the Council of Ephesus starting only later in June 431. Thus, he is truly a Saint of the Universal Church, even though he is virtually unknown among Orthodox Christians.

https://orthodoxreflections.com/the-life-of-our-father-among-the-saints-zayya-the-blessed/