Carolyn Pressler, in her 2002 commentary for the Westminster Bible Companion series, suggests that readers of the Book of Joshua should give priority to its theological message ("what passages teach about God") and be aware of what these would have meant to audiences in the 7th and 6th centuries BCE. Richard Nelson explains, "The needs of the centralised monarchy favoured a single story of origins combining old traditions of an exodus from Egypt, belief in a national god as 'divine warrior,' and explanations for ruined cities, social stratification and ethnic groups, and contemporary tribes."