{ 1 } - the analysis and appraisal of arguments.
{ 2 } - theory of knowledge.
{ 3 } - reasoning about the existence of God.
{ 4 } - theory of value.

Reformed epistemology is a view about our knowledge -- a view that has roots in John Calvin (an important figure in the Protestant Reformation).

Reformed epistemology holds that that it's rational to accept the existence of God as a "properly basic belief" -- one that needs no argument on its behalf.