Narsai,in his Metrical Homilies, shows that the Eastern Church was active in preaching the gospel to Gentiles. This surprises me positively. But I would like to know more about the terms he uses: by «Gentiles», I think, that he means the unbelievers. What does he mean by the «House of Abraham»? Does he mean the Jews who believe in the Messiah? Or the believers of the Gentile Church? How did the Eastern communities understand the relationship of their communities to Israel? Did the Jews have a place in their theology, or were they replaced by the Church? Were there any Judeo-Christian / Messianic churches left in the Near East? They were certainly a reality in the first and second centuries, but after? The Orthodox were negative towards the Jewish Christians in the councils, what about the excluded Eastern Churches? Under Islam, the relationship between Christians and Jews became hardly easier. Are there sources for these questions?