A thematic approach is based on related ideas; a lexical approach is based on individual words. The difference between them can easily be appreciated by considering the theme of “assurance”. A word-based approach would be limited to identifying biblical passages in which words such as “assure” or “assurance” appear. A thematic approach, however, goes far beyond this and explores all the basic elements of the theme. It identifies its basic ideas, its presuppositions and its consequences, in order