How can one deal with the different Islamic groups (Sunni, Shia, Sufi, Ismaili, etc.) regarding the issue of allowing them to use the mosque for activities and celebrations (such as Mawlid and Isra wal Mi'raj) that have no basis in the Quran and Sunnah, given two proposals: one to separate and build a mosque based on the correct creed, and the other to remain as one community to avoid negative repercussions on the new generation?

The Prophet informed that the Ummah would split into 73 sects, all of them in the Fire except one, which is the Jama'ah (the main body of Muslims). If a sect is among those that have deviated from the religion of Islam, then it is not permissible to cooperate with it. However, if it claims adherence to the Sunnah (definition), then cooperation with it is possible in matters where it aligns with the truth. Cooperation should be avoided in matters where it contradicts the Sunnah, while striving to unite people upon the Qur'an and Sunnah and overlooking issues of jurisprudential difference.