Is he who does not declare as disbelievers those who ascribe themselves to Islam from among the polytheistic people of Sufism a disbeliever, and what is the evidence for that?

A Muslim must be deliberate and not rush into excommunicating others, due to the gravity of the matter and its tremendous consequences. If a person's disbelief is established, a separation occurs between him and his wife, he is prevented from inheriting, and he deserves eternal damnation in Hellfire. Therefore, Islamic law prohibited excommunicating Muslims before ensuring that the conditions are met and impediments are absent. It is not permissible to excommunicate a Muslim whose Islam has been established with certainty, except after establishing the proof and removing any doubt.