The paper has focused on grudge, as one of the most important religious emotions. Firstly, the nature of this concept and its difference with the concept of hatred, kinah, are examined and, then, moral norms governing it in the religious relations will be explained. As founded in the study: the concept of grudge differs considerably with that of hatred; hatred has an immoral character, while religious grudge is a moral emotion appearing in the cases of breaking ethico-religious values; again, in the scene of action, one, claiming religious grudge, may make his/her personal bad intention clear. Various principles such as avoiding optimism when grudging and badly-intended benevolence, and avoidance of prejudice, may be regarded as necessary norms providing this affection`s nature as opposed to immoral state. This research has intended to take steps toward establishing this moral affection properly in a religious society. The study has been performed on the Qur'anic verses and narratives in the field along with some ethical and psychological teachings related to the issue. Accordingly, the study has used a documentary method and taken an analytico-descriptive form.