What are our duties towards trustworthy scholars, and is it obligatory to adhere to a ruling or fatwa issued by them, even if the heart and mind do not approve of it, especially given that some claim what they say originates from "a group of scholars" or "a trustworthy scholar" without disclosing their identity?

If an ordinary person is conveyed a fatwa from a trustworthy scholar, and the ruling given in the fatwa is based on a consensus (ijma') or supported by a text from the Qur'an or Sunnah, then it is not permissible for them to violate it. However, if there is a difference of opinion regarding the matter, the ordinary person may follow the scholar whose knowledge and piety they trust, because there is no condemnation in matters of ijtihad (independent reasoning). Objecting to the fatwas of trustworthy scholars based on mere personal opinion is not the action of the people of faith.