Let's begin in Genesis 3. I want to show that exile is a form of punishment that God has used from the very beginning. Here in Genesis 3, in the book of beginnings, we have the first instance of exile imposed by God Himself.
Exile from the Garden of Eden, from all that was wonderful and good that God had created in that perfect environment in which He had placed Adam and Eve and they couldn't go back, ever. God placed an angel with a flaming sword that would turn whichever way we - man - juked to get back, and it would deny us paradise for now.
This context shows three reasons we can glean to determine why God uses exile. The first one is very evident - it was punishment for their sins. Look, you guys took the tree of the knowledge of good and evil when I said you shouldn't take of it. That's sin. That's breaking a direct command of God. So exile was the punishment.
What else is here? Well what did their exile do? It separated them from access to Him. So the second thing that exile does is separate man from God. Now He doesn't like that. He doesn't want to be separated from us, but because of sin, it just happens. It has got to happen because He does not like sin in the least. So it's kind of a corollary to the first point. The first point is directly because of sin and the second point is to separate us from Him.
The third point is one you have to read into it, but it's obvious from the intent and the way God is. God imposes exile to spur repentance because it should be the natural inclination of men who have known God and all the glorious things that we can have in His presence, to get back into His good graces.
So the first point is we are exiled because of sin. The second point is we are exiled because we have to be separated from God. And the third point is because God wants us to repent.
This encapsulates the effects of sin. It is separate from God. Adam and Eve wanted to hide themselves from God. Their perspective on the things of life had changed. Now we find that because of these things, God does this:
Now the separation is very clear, and mankind is cut off from God and cut off from the Holy Spirit. The episode there in the garden of Eden, as it is recorded, makes it very clear that it was mankind that took themselves away from God, not the other way around. There are no indications in Genesis 3 that Adam and Eve wanted the breach to be healed - not at all. All they did was justify themselves. Adam blamed Eve and Eve blamed the serpent.