A Muslim Leader in Brooklyn, Reconciling 2 Worlds
First of three articles in series An Imam in America; profile of Egyptian Sheik Reda Shata, who became leader of Muslim congregation in Brooklyn one year after Sept 11 terrorist attacks; finding ways to reconcile Muslim tradition with American life has worn him down and opened his mind; few of America's imams recruited from abroad are prepared to lead community on margins of American life; his collapse before his congregation one day has led to citywide training program for imams, blending Islam and psychology; photos (L)