How did sickness come into the world?

Before talking about healing we need to know the origin of sickness - how sickness came into the world.  Because healing is about reversing sickness right?  Right?  RIGHT?

Some words to meditate on, then tell me what it speaks to you:

Genesis 2:16,17 emphasis 17
Leviticus 26:14-46, emphasis 14-16
Deuteronomy 28:15-68
James 5:16, emphasis on verse 15, 18, 21, and 22

So, how did sickness come into the world and how can you reverse it?  You heard it before, but do you really believe it?  You say you believe it, but how have you demonstrated it in your life? when you have been sick?