Complex sentence: He became a committed Christian in November 1978; he helped pioneer the Hills Christian Life Centre in 1983 and was appointed the worship pastor for the related Hillsong Church and was convenor of their annual conferences from 1987 to 1995.
Split into simpler sentences: He became a committed Christian in November 1978 and in 1983 helped pioneer the Hills Christian Life Centre which later became part of Hillsong Church. He was appointed as the church's worship pastor and was also the convenor of their annual conferences from 1987 to 1995.