Out of Egypt
What happened when God led the people out of Egypt? - they were in the wilderness for 40 years. Why does God keep us in wilderness years sometimes? Perhaps it's because He wants us to be free of all we carried, thoughts and beliefs, from a previous period in our lives - like the Israelites needed to be free of all they carried with them from Egypt in thoughts and ways of living. Because He wants a people for Himself. Because He wants it to be all about Him and not about us; that Grace may abound. So that He can do a new work, a fresh work, new wine in new wineskins. If we are still carrying our old mindsets then He cannot do things the way He wants to.
See picture in its original context at: http://www.flickr.com/photos/lapidim/143590276/