Is it obligatory for a Muslim youth to belong to an Islamic group that claims to be engaged in Islamic work, despite its contradictions and failures?

A Muslim must adhere to the religion and the legitimate methodology. Belonging to Islamic groups is permissible or desirable if they are upright upon the methodology of the Sunnah and adhere to it, for the sake of cooperation, brotherhood, and supporting the religion, but it is not obligatory. However, if the group deviates from the Sunnah and the sound methodology, it is not permissible to join it.