The aim of this paper is to investigate how an ethical community can become the essence of a true Church from Immanuel Kant's point of view. Our starting point will be the end-point of practical reason, namely the Sovereign Good. We will see how morality becomes the path to achieving this greater Good, through the virtuous action of man belonging to two different worlds, who, in order to overcome his limited cognition, postulates the existence of a supreme being. Secondly, we will deal with the transition between morality and religion, starting from freedom, moving between the concepts of the kingdom of ends and ethical community, through a historical faith and an exemplary prototype that will lead us to an idea of the visible and invisible Church. We will end with rational faith and critical theology, culminating in a moral religion and an ethical community that is free, rational and essential to the true Church.