The discipline of Bible exposition is interested in biblical theology and tracing major themes in Scripture. So I am often fascinated by the themes that different interpreter identify in either books or in the Old or New Testaments. Marty Stevens in a recent book identifies four major theological themes in the Old Testament. The themes (helpfully alliterated) are:
Creation Covenant Cultus Character
Marty E. Stevens, Theological Themes of the Old Testament, Creation,Covenant,Cultus, and Character (Eugene, OR: Cascade, 2010).