What is the ruling on a da'i who calls to Allah with legal evidence but has some deviations in his own conduct?

Question:
The questioner asks: What is the ruling of the Shari'ah regarding one who claims to be a da'i, engages in calling to Allah, commands prayer and hijab, and presents legal evidence, but you find that he does not apply the commands of Allah the Exalted in his own life? For example, you find him with a shaved head, wearing what is called pants, and sitting in mixed gatherings of men and women.

Answer:
Yes, he has fulfilled an obligation, which is calling to Allah and enjoining good and forbidding evil, but he has neglected an obligation, which is acting upon what he says. So his sin is upon him; his sin is upon him. But we accept the truth from him. We accept the truth; if he speaks the truth, we accept it, and we do not look at whether he acts upon it. The truth is accepted from whoever brings it. The Prophet (peace and blessings be upon him) accepted it from the Jew who said, "You are associating partners with Allah when you say, 'What Allah willed and what Muhammad willed.'" The Prophet accepted this and forbade his Companions from saying this phrase, even though he was a Jew. The truth is accepted from whoever brings it, and the fact that he does not act upon it is his own sin.