Complex sentence: The intention of the authors and editors of Samuel and Chronicles was not to record history, but to promote David's reign as inevitable and desirable, and for this reasos there is little about David that is concrete and undisputed.
Split into simpler sentences: The intention of the authors and editors of Samuel and Chronicles was not to record history, but to promote David's reign as inevitable and desirable. For these reasons there is little about David that is concrete and undisputed.