The way I have heard it explained, G-d created perfection, after the fall the earth was corrupted, there was no sickness, accidents, crime, etc before the fall these are all things that occurred after the fall, including the genome, which has been corrupted as well, this explains healing where G-d not only heals the body, He heals the genome as well.
So, all sickness, disease, accidents, etc, anything that isn't love, joy,peace, etc, isn't from the Father, they are from the other side.