What is the difference between the world as an enemy of the soul and the world as the place in which we live?

Like Jesus said, you are in the world in the sense that you live here, but do not be conformed to the world. This is part of the punishment for Adam's sin: we live in a world that is sometimes more like hell than heaven, and Jesus tells us his kingdom is not of this world, so we are limited in what we can do to improve it. From the day you are born to the day you die you are going to suffer, and much of it has to do with how the world and its mentality work. You can get mixed up with that world, thinking that to get anywhere you must conform to what the world tells you politically or financially, and that is how the world bombards you, and it is hard to escape. That is why people ran off to monasteries and convents; they loved God and wanted to serve him, and the only place they could find to do it was some vacuum out in the desert where they could live off the land, bide their time, take their suffering, and then die and go to heaven. There is no place you can go to escape it, because if you go from point A to point B, the same thing will be at point B that was at point A, maybe greater, maybe less, but still there.