In a world of dwindling sentence length and complex sentence structures, the semi-colon has fallen on hard times. It is too bad. It has the ability to stop the reader ever so slightly, and indicate that while there is some sequence of thought (much like a comma), there is also a stop (but of less strength than a period).
Case in point is Romans 9:4. Paul is expressing his deep desire for the salvation of the Jewish nation. In reciting their privileges he says, “They are Israelites, and to them belong the adoption, the glory, the covenants, the giving of the law, the worship, and the promises” (ESV). It reads as a sequence, a series of privileges given to the Jewish nation.