Sickness is very real and is a condition that occurs to all humanity. I can say with total certainty that no person has lived an entire lifetime without being ill at one time or another. A great majority die due to illness. Only a very few people simply die of old age (just being totally worn out).
No part of the human body is free from some kind of sickness, from the top of the head to the soles of the feet. Doctors have big tomes listing hundreds of thousands of maladies that afflict people.
I sincerely believe that sickness is a great mystery! Why? Because why do we have to get sick? There are different reasons. Some believe that sickness is punishment for our misdeeds, or the sins of our fathers. Others believe that the Devil is the cause. Why? Because Satan hates God and therefore hates us because we are God’s people! Does this make sense? Not to me. For some people, yes! But why do we have to be victims of the Devil?
The hardest thing to understand is when a child has a serious sickness that results in his or her death! They are innocent, but they suffer! It is devastating for the parents and relatives. I do not understand! When Jesus was on earth at one time he said “You will have tribulations”, which I believe includes sickness.
Footnote: The worst of sickness, I think, is mental sickness. Most of the mass murders and even the death of one person by the hands of another are the result of someone who is mentally unbalanced. And included among these “sick” people are terrorists and fanatics!