As the Children of Israel trudged across the Sinai desert, they were acting out an archetypical pattern that is repeated again and again in scripture. This is sometimes called the Exodus pattern or the type of the wilderness journey. Though entire books have been written on this type, in its bare bones form it goes like this: A covenant people live in a city or land that represents the world. This is a world crass and unrighteous, materialistic and wicked, that has turned away from God. In order to spare the righteous and count them as his own peculiar treasure, the Lord calls them out of the world before it is about to be destroyed. It is both his blessed way of saving and schooling them.
His goal is to take them to a promised land where he can make them his "peculiar treasure," but in order to obtain this new land, a wilderness journey is required. The journey is difficult and tedious, putting even their survival on the line and driving each member at one time or another to the very limits of his physical or emotional endurance. Availability of food is in question; water is scarce and only delivered through miraculous means. Yet what happens on this journey is straightforward. The Lord has taken his people out of the world, now he must take the world out of his people.