Tradition

Imam Jafar Sadiq (a.s.) informed Muhammad ibne Muslim: Everyone who wishes to gain proximity to Allah the Almighty with his worship in which he struggles and does not have an Imam for himself from Allah’s side, then his efforts are not accepted and he is deviated and in confusion and Allah abhors his deeds and if he dies upon this condition he will die a death of disbelief and hypocrisy. And know that O Muhammed, surely the unjust Imams and their followers are deviated from the religion of Allah. They are deviated themselves and also deviate others. ‘Then the actions which they have performed are like ashes on which the wind blows hard on a stormy day; they shall not have power over anything out of what they have earned; this is the great error.’ (Sure Ibrahim (14):18).
Wasaail al-Shia v 1 p 118