In this task, we ask you to elaborate the sentence without changing its general meaning. You can do so by explaining further the input sentence, using more precise wording, adding qualifiers and auxiliary information etc.
Q: The Assyrian Church of the East also called Holy Apostolic Catholic Assyrian Church of the East is a Christian church .
A: 
The Assyrian Church of the East , officially the Holy Apostolic Catholic Assyrian Church of the East , is an Eastern Christian Church that follows the traditional christology and ecclesiology of the historical Church of the East .