Kathy -- your knowledge of history and geography is abysmal -- Christianity spread throughout the ROMAN Empire -- in Judea, in Egypta, in Syria and also in parts of the Parthian Empire -- in Mesopotamia, in Persia proper. The southern part of the ARabian peninsula was part of the Ethiopian Empire while Mecca, Medina etc, the eastern and northern part was Persian (northern Oman, Bahrain, the UAE etc.), the middle of the Arabian peninsula was not claimed by anyone as it was more or less worthless to them. Christianity did NOT spread there -- though Gnostic and Arian thoughts were widespread there (they are both Christian heresies -- Islam too is a Christian heresy)
I admit my knowledge is worse than abysmal. Your posts are very informative. (Although I think a lot of this history has been revised by the revisionists).