Theology 101

I am intrigued. What does a theologian study? Surely comparative religion is sociological, the existence of supernatural beings is philosophical metaphysics (or ontology?) and the development of religion(s) is history? What does a theologian study? How many angels can dance on the head of an imam? Is christian theology like the chemistry of nucleotides? Just a sub-set of the wider study of bio-theology? Have you got it yet? Can you see the absurdity?