It is narrated from Sayyiduna Awf bin Malik (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: "My Ummah will split into seventy-some sects. The greatest trial for my Ummah among them will be people who measure matters by their own opinion, and so they will make the unlawful lawful and make the lawful unlawful."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 15181