Dear John Francis,
Sometimes some Orthodox write as though 'understanding' was not essential; here a linguistic confusion enters into things.
If by that word one means full comprehension of the mystery of the Incarnation and our salvation, then I would agree that we are never going to get there; nor is it needful. But if one means a comprehension of the Scriptures, their import and the language of the Liturgy, then I would argue that we do need to 'understand'.
On another forum an ex-episcopalian who became EO many moons ago asked why, since he had been expected to learn old Church Slavonic, I felt able to become Orthodox without it. My answer was that Acts 15 makes it plain that the yoke should be fixed lightly on the newcomers. If Sts. Cyril and Methodius had taken that point of view then there would have been no service in Old Church Slavonic; and I wonder how many Slavs would have been prepared to learn old Greek?
This is all to confuse the package with its wrapping. Christ spoke in Aramaic and Greek, but His message is universal. Even Latin did not work as a unifier - the Greeks didn't care for it, after all.
One of the many wonderful things about the BOC is that one can worship the Lord in the beauty of the Liturgy of St. James - and understand what one is saying. Having listened, on line, to services in Syriac Churches, the words carry a powerful charge, but I do not understand them. The Coptic Church wisely spotted that Christ came to make Christians, not Copts or Russians - and to adapt a saying of St. Paul, in Him there is neither Old Church Slavonic nor Koine Greek.
In this is love, not that we loved God, but that He loved us and sent His Son to be the propitiation for our sins. (1 John 4:10)