Possible Clues:

• Split in southern church is over mass
• Breach within a Chruch
• Rift ... or, read in three parts, a description of this puzzle's theme
• Dividing of group into opposing factions
• Result of ultimately fallacious church doctrine?
• Southern church is encountering first major split
• The Protestant Reformation, e.g.
• It may create second church with distinct set of beliefs
• How the S.C.'s thousand is split
• Split in Brunelleschi's masterpiece