Job is a book from the Old Testament / Hebrew Bible - depending on your religious background. Job lost pretty much everything, including his health (eventually). When this happened, he responded in the most amazing way. According to Job 1:21, after the death of his children and wealth, he stated the following:

“Naked I came from my mother’s womb, 
and naked I will depart.
The LORD gave and the LORD has taken away; 
may the name of the LORD be praised.”

In light of this Job is an example of unwavering faith in God. In other words, his faith is not rooted in his circumstances, wealth, health, or any other earthly thing. His faith is in God period. This is why he is able to say these words.

As the book progresses, many of Job's friends try to give him counsel - all bad. Job does not listen to them. At the end, God reveals himself to Job and Job is speechless in view of the glory and power of  God. The book ends without a clear answer on human suffering. It just simply says that man must have faith in a God who knows.