Advice from The Messenger (ﷺ)

On the authority of Al-ʿIrbāḍ bin Sāriyah who said that Allāh's Messenger ﷺ admonished us with an admonishment by which the hearts became fearful and the eyes shed tears. So, we said: "Advise us, O Allāh's Messenger!" He ﷺ said, "I advise you all to fear Allāh and to hear and obey (the rulers) even if an Abyssinian slave was made to rule over you. For verily, those among you who will live after me (after my death), will see many differences/conflicts. So, upon you is to follow my Sunnah and the Sunnah of the Rightly Guided Caliphs. Hold onto it with the molar teeth and beware of the newly invented matters. For indeed, every newly invented matter is a bidʿah (innovation within religion) and every bidʿah is misguidance.