This paper aims at examining the meaning of freedom of religion in the perspective of Islam, the Universal Declaration of Human Rights (UDHR) and Indonesian legal system. The meaning of freedom of religion is examined and compared in these perspectives because there is a recurrent problem regarding this human right in Indonesia which is mostly populated by Muslims. A phenomenon of aliran sesat (diverted religious organizations) emerge nowadays ripping religious harmony among people. These diverted religious organizations and their supporters claim that it is their right to do what they believe because it is protected by the Universal Declaration of Human Right and Indonesian law. However, the majority of Muslims consider them as humiliators of the religion itself, so they urge the government to stop and punish them. The government seem to be hasitated to enforce the law, thus, from one side the government is accused of not protecting and ensuring these diverted religious organizations in using their right and freedom, while from the other side it is accused of neglecting those who humiliate religion and break the others human rights without any punishment. This study finds out that the law regarding freedom of religion in Indonesia is sufficient and what is needed is just the enforcement of this law to ensure the rights of all people. To reach the goals of this study, a descriptive-analytical approach is employed.Keywords: Freedom of religion, Islam, Human Right, Indonesian Law and Aliran Sesat (Diverted Religious Organization).