How can the feeling of intense jealousy for the religion of Islam be overcome, and what is the way to deal with the current reality of Muslims' leniency in applying teachings and the marginalization of the role of scholars?

Jealousy (Ghirah) is a sign of faith. Allah loves jealousy concerning doubt and dislikes it in the absence of doubt. Jealousy for the religion is a good thing, but one must be moderate in it, for religion is ease. It is wise to be moderate in your denunciation of evil, because some evil is lesser than others, and what cannot be achieved in its entirety should not be abandoned entirely. We ask Allah to assist you in doing good. And remember the saying of the Prophet, peace and blessings be upon him: "For Allah to guide a single man through you is better for you than possessing red camels."