In this paper I attempt to systematize Husserl's remarks in the Nachlass on the study of religion. I will not be dealing primarily with his own philosophical theology which he regards as the culmination of his transcendental phenomenology, but rather with what he thinks religion is and what is studied when people study religion. I will first briefly discuss how religion is a developing cultural phenomenon which comes to have a relationship to philosophy and reason. This leads us to the consideration of a variety of senses of theology.