On 13 May 1979, he was ordained to priesthood taking the name Mesrob and was commissioned pastor of Kınalıada, one of the Princes' Islands in the Sea of Marmara in Istanbul with a small Armenian community.

[2] In July 2008, it was announced that Mesrob Mutafyan was suffering from Alzheimer's disease and he withdrew from all his duties and from public life; however he still officially remained patriarch and archbishop.

[5] As tensions escalated leading to the resignation of the head of the synod of the patriarchate Bishop Sahak Mashalian, Karekin II, Catholicos of All Armenians summoned the lead clerics including Ateşyan, Mashalian and Bekdjian from Istanbul to Etchmiadzin for a mediated solution in February 2017.

[6] On 15 March 2017, the synod elected Archbishop Karekin Bekdjian, the Primate of the Armenian Church Diocese of Germany as Locum tenens or Patriarchal alternate (Deghabah).

As a sign of respect Patriarch Abba Seraphim directed the British Orthodox Church to observe forty days of mourning.