Among the earliest known sources from the Persian Church, the 4th-century Demonstrations of Aphrahat reflect a form of Christianity much closer to its Jewish roots than contemporary Western forms.
Wisdom from east of the Romans (Greeks) before the great councils
As Aphrahat says, the Faith is a pearl the luster of which appears no matter from which side one views it. Of course, the Church Fathers, though shining lighys, were not infallible. Neverthe less, much profit may be gained by reading the Demonstrations. I wish the compiler had shared them. Not that I read them all, but some that were left out I would have liked to read.