Following or Disregarding; the criteria is Quran

Hawzah News Agency - Ali ibn Ibrahim has narrated from his father from al-Nawfali from al-Sakuni from abu ‘Abdallah who has said the following. “The holy Prophet (s.a.),

«إِنَّ عَلَى كُلِّ حَقٍّ حَقِيقَةً وَعَلَى كُلِّ صَوَابٍ نُوراً فَمَا وَافَقَ كِتَابَ الله فَخُذُوهُ وَمَا خَالَفَ كِتَابَ الله فَدَعُوهُ.»

“Over every truth there is a reality and above every valid issue there is light. Whatever agrees with the holy Quran you must follow it and whatever does not agree disregard it.”

Al-Kāfi, v.1, Book 2, Chapter 22