Complex sentence: It quickly proved to be quite popular as a contemplative song at Catholic Masses as well as at Protestant services; it is now sung in churches of many denominations including Pentecostal churches and was performed at many of the funerals of victims of September 11.
Split into simpler sentences: It quickly proved to be quite popular as a contemplative song at Catholic Masses as well as at Protestant services. It is now sung in churches of many denominations including Pentecostal churches and was performed at many of the funerals of victims of September 11.