Source: The Economist BY ERASMUS  AS ORTHODOX Christian leaders prepare for what has been billed as their most important gathering for centuries, they have many problems to wrestle with. One, as widely reported already, is the chronically uneasy relationship between the two best-known of those leaders, the Istanbul-based Ecumenical Patriarch, Bartholomew I, and Patriarch Kirill of Moscow. It is Patriarch Bartholomew, in his capacity as “first among equals” in the Orthodox hierarchy who is organising and hosting the Synod; but many eyes, both wary and admiring, will be on his Russian guest, who along with his huge entourage has just toured South America, and…