«ما تواد اثنان في الله فيفرق بينهما إلا بذنب يحدثه أحدهما»
The Prophet (peace and blessings be upon him) said:
"Whenever two people love one another for the sake of Allah, separation comes between them only because of a sin that one of them commits."
Hadith Referenceصحیح الجامع الصغیر / حرف الميم / 5603