Narrated Abu Huraira: Allah's Apostle said, "The Day of (Judgment) will not be established till there is a war between two groups whose claims (or religion) will be the same."
Hadith ReferenceSahih Bukhari / The Book of Virtues / Hadith: 3608
Hadith Gradingمحدثین:أحاديث صحيح البخاريّ كلّها صحيحة