"The proudest boast of Celtic monasticism was that, in the words of the Antiphonary of Bangor:
This house full of delight
Is built on the rock
And indeed the true vine
Transplanted out of Egypt."
William Dalrymple, "The Egyptian connection," New York review of books 55, no. 16 (October 23, 2008): 79, online at http://www.nybooks.com/articles/21979. Pp. 79-80 especially are a popular summary of "Coptic influence on the Celtic Church" on the one hand, and emergent Islam on the other, such that "both the art and sacred calligraphy of Anglo-Saxon England and that of early Ummayad Islam grew at the same time out of the same East Mediterranean culture compost and common Coptic models": "if a monk from seventh-century Lindisfarne or Egypt were to come back today it is probable that he would find much more that was familiar in the practices and beliefs of a modern Muslim Sufi than he would with, say, a contemporary American evangelical. Yet this simple truth has been lost by our tendency to think of Christianity as a Western religion, rather than the thoroughly Oriental faith it actually is." Practices, yes. But core beliefs? I don't know Sufism well enough to judge. Two further tidbits: "The Irish wheel cross, the symbol of Celtic Christianity, has recently been shown to have been a Coptic invention, depicted on a Coptic burial pall of the fifth century, three centuries before the design first appears in Scotland and Ireland" (here Dalrymple cites Walter Horn, "On the origins of the Celtic cross," in The forgotten hermitage of Skellig Michael (University of California Press, 1990)); and "The theology of the Desert Fathers was deeply austere, with much concentration on judgment and damnation, a concern that they passed on to the Irish monks."