Just a brief testimony to the value of systematics. I converted out of studying Calvin's Institutes. I was running a University Tutorial on Reformation History as part of a Medieval/Rennaissance Unit towards a Arts Degree. Deciding to master my subject matter, I started up on the Institutes which I borrowed from the Uni library. I converted in the light of the doctrine of justification, which simply blew away anything else I had ever read. I had never even vaguely understood Christianity until then, and its hard to accept that which you don't understand.
After Calvin, I read Berkhof, whose systematic I found by chance in a second hand shop, and I read Hodge before I actually met anyone (else) who believed in an infallible Bible, about 4 months later, when a young Presbyterian lass tried to convert me on campus. You can imagine my joy at finding out that there were people who believed in Justification and weren't dead. You can imagine her surprise when I shortly asked her if she was Supralapsarian or Infralapsarian.
Trew story. Praise God for his mercy.
Let me mention the apologetic power of systematics - telling me that Jesus loved me meant nothing until I understood what that meant in the light of what he had done.
let me also recommend: John Brown of Haddington's Systematic (Christian Heritage Books 2002). overwhelming scriptural references for all the classic doctrines makes this excellent in controversy.
Ursinus - Commentary on the Heidelburg Catechism (Presbyterian and Reformed). A classic.
