My purpose is to communicate to students what the goals are as budding scientists and what they will hopefully be able to understand by the end of the semester. Economic theory helps to shed light on the important issues. At each step in the development of theory, I refer back to the issues and explain how the theory just taught sheds light on these issues. The empirical component helps us to sort out which theories can be applied usefully to understanding real-world issues.
My experience with economics classes, at both the undergraduate and graduate levels, is that the theory component is often large relative to the issues and empirical components. In these classes, the issues become theory related, e.g., are models with perfect foresight stable? In the end, students learn much theory, but have little idea of the meaning and relevance of what they have learned. In such situations, the material becomes merely “stuff” that students try to force into their heads. Nothing is more effective at killing curiosity and engagement on the part of students than teaching them stuff.