When I was in highschool I took an internship with the pastor of the church which ran the school in which I was enrolled. It was a fantastic relationship and mentorship. One of the things that was stressed in that course was the merits of exegetical preaching over topical preaching. While both are alleged to have their merits, topical preaching was framed as the weaker public form because it was seen as supporting a theology which was ungrounded. It gave opportunity for convenience in theology. However, there are times which social groups need to address specific topics. In fact Paul addresses specific topics at churches in his letters. In this sense then, theology when systematic, must look at issues topically. It must also look at all supporting arguments to make sure those arguments are exegetically or socio-culturally-contextually accurate. In these cases contextual relevance and interpretation is important. The topic of the discourse unit is paramount in the application of the verse. Verses markers in scripture are purely indexical. Understanding the topics the Bible discusses and why those topics are discussed allows for accurate and appropriate application in new social environments.
Topical vs. Exegetical