When, by decree of Emperor Constantine in 325, the persecution of Christians largely ceased, there was cause for rejoicing.   Official sanction, however, brought its own temptations-laxity and worldliness-inspiring a great exodus into the desert which provided fertile soil for the ascetic exploits of those who thirsted, like the martyrs, to lose their life for Christ. Among the most renowned of these early desert-dwellers was St. Macarius the Great.  So lofty was his spiritual attainment that in recording