Is it permissible to provide financial assistance to a sect that promotes Bid'ah (innovation in religion) and Sunnah, or should assistance be restricted only to those who follow the methodology of the righteous predecessors (Salaf Saliheen)?

It is legislated to help the group that follows the methodology of the righteous predecessors, as this is cooperation in righteousness and piety. As for the group that calls to innovation (bid'ah) and the Sunnah, it is permissible to help them in actions that conform to the Sunnah, while advising them and clarifying the truth. However, it is not permissible to help them if the destination of the money spent is unknown, for fear that it might be spent on innovative matters such as "celebrating the Mawlid" or "printing a book that calls to innovation."