Previous research indicates that spirituality expressed in tradition-specific terms may initiate, invigorate, and integrate Muslim religious commitments, suggesting a 3-I Model of Religious Spirituality. In a test of this model, Islamic seminarians, university students, and office workers in Iran responded to Muslim Experiential Religiousness, Religious Orientation, and mental health scales. The tradition- specific spirituality of MER displayed correlation, moderation, and mediation results with Intrinsic and Extrinsic Personal Religious Orientations that pointed toward initiation, invigoration, and integration effects, respectively. MER also clarified (...) the ambiguous implications of the Extrinsic Social Religious Orientation. These data most generally confirmed the heuristic potential of the 3-I Model. (shrink)