Possible Clues:

• Church dignitaries
• Note about marriage guidance counsellors supplied by clergy
• They tell in the postscript how to study 1 across
• This tells at last about high churchmen
• High-ranking clergymen
• In the postscript it's all about the dead high churchmen
• Hierarchs
• Bishops making report in addition to writing
• The piano tells how high they are in church
• Bishop's colleagues