‘Whoever lives for long after me will see much differing. So, upon you is to adhere to my Sunnah and the Sunnah of the Rightly Guided Caliphs. Hold fast to that and bite onto it with your molar teeth. And beware of the newly introduced matters into the Religion for verily every newly introduced matter is an innovation.’
Hadith 28, 40 Hadith an-Nawawi