“IT can be both. What you must appreciate is that earthly life provides a polarity which is not available in our world. In our world people of the same stage of evolution are in the same spiritual sphere or plane.
In your world you are mixing all the time with people of varying stages of evolution. You get opportunities for all the opposites to be encountered. Thus you can have light and dark, heat and cold. All this is the purpose of earthly life. It provides the means by which the soul comes into its own.” ~ The Silver Birch Book Of Questions & Answers, P.134