The present article deals with one of the most important and most affected issues in social relations. The arena of social life is a great field of judging the behaviors, traits, and motivations of others. The believers in God ought to do their best to judge justly and truthfully in this arena. Therefore, we need valid principles and criteria for correct moral judgments so that, by observing them, the deviation in judgments can be reduced and we can perform our duty in this respect. In order to understand the principles of moral judgment in social relations, this article has gone to the sources of revelation and attempted to explain and study the principles by extracting them from the verses and narrations via a descriptive-analytical method, and correspondingly attained such principles as having sufficient and certain information, justice and fairness, attention to existential differences and capacities of individuals, and non-generalization of the verdict in similar examples and cases.