This paper deals with the role of religious parties in the Indonesian political system. It demonstrates the importance of Islamic parties and explains the declining significance of Christian parties in the last dozen or so years. In the conditions of deep religiosity in Indonesian society, religious parties are understood as political parties that meet the following criteria: 1) are created by and for the followers of Islam or Christianity, respectively, 2) serve to pursue their interests (specifically the interests articulated by the political and religious elites of religious communities) and 3) build their programs based on the principles and values of faith, and also promote and protect them.