Faith has been regarded to be one of the most important elements in religions. Explaining the essence and position of faith, therefore, has formed one of the most essential problems in theology. The paper focuses on the view of Sadra in the field. Therefore faith has been defined shortly and its essence, its subject, its different kinds and degrees have been brought into consideration. It has been concluded that Sadra does not know faith as pure heartly belief. Yet it designates some heartly belief to principles, expressing it in speech and performing the basic rules by the parts of the body. In the view of Sadra, the subjects of faith include Allah, angles, holy books, messengers, resurrection.