Possible Clues:

• Foreign niece's mum produces philosophy in favour of religious unity
• United Christendom movement
• Christian Union in immense high church-wide movement
• Movement to unify the Christian churches
• Movement to unite Christian churches
• From Eminem music I'm missing movement for reconciliation
• Miscue men involved in movement towards Christian unity
• Movement to promote better understanding between religions
• Miscue men engaged in movement for Christian unity
• The movement towards worldwide Christian unity