Complex sentence: Cyril Navin (also a native of Ireland) arrived at St. Cyril's and served as pastor from 1971 until 1996 when he became Pastor Emeritus.
Split into simpler sentences: Cyril Navin (also a native of Ireland) arrived at St. Cyril's and became the pastor from 1971. Navin remained the pastor at St. Cyril's until 1996 when he became Pastor Emeritus.