Paying attention to the relationship between belief and behavior can explain apostasy in a different way. The current research is trying to answer this question, what effect does Mulla Sadra's view on the relationship between belief, behavior (queen) and behavior (action) have on his explanation of apostasy? The purpose of the research is to explain Sadra's view of the possibility of apostasy, which is followed by descriptive-analytical method. According to Sadra, in the upward course of conduct (movement from action to knowledge) and in the position of action or habit, that is, before the repetition of actions reaches the level of penetration and queen, the possibility of apostasy is imagined; Because at this stage, a change in the soul is conceivable, and any attribute that has not dominated and mastered the human soul and has not become the queen of the soul, has not reached the necessary level, and it will be easy to do actions contrary to that attribute.

In the downward course of conduct and when the soul has become accustomed to doing it due to its persistence and has reached the stage of penetration, apostasy has no meaning and the person's actions are the manifestation and fruit of his knowledge. Therefore, if the ego reaches the rank of queen and permeation, apostasy will no longer be possible. But before reaching the stage of penetration and queen, apostasy is possible.