In reply to a question Ameerul Momineen (a.s.) informed – The minimum deviation is when a person does not recognize Allah’s Proofs and Witnesses on His Servants – those whose authority and obedience has been made obligatory by Allah.
Al-Kaafi v 2 p 415 Isbaat al-Hudaat v 2 p 34 Al-Burhaan fi Tafseer al-Quran v 2 p 107 under Surah Nisa (4): 59 Behaar al-Anwaar v 66 p 17 Kitaab Sulaym Ibn Qais v 2 p 616