Hardship is nature's way of weeding out the faint of heart.
Quite frequently, with the spreading of death and destruction across our world, the question arises: how, if there exists a merciful almighty power of any kind, could such calamity be allowed to happen?
Logic often supersedes emotion, in fact, in its quintessential acts independently. The laws of evolution as they have been permitted to be known in generalization often emphasize upon the fundamental, 'survival of the fittest'.
The greater power, if so exists, may be not more than a scientist that dabbles in a hobby, or perhaps even a passion, for art - for the beauty encountered in much of our daily life is such that we cannot but help remark upon it. But scientist he most assuredly is, for if he has created anything, it would be the laws which govern our world, physically, metaphysically, and perhaps metaphorically - and otherwise.
He is the programmer, writing code which easily loop, executes, and performs conditional if and then commands. If it goes up, then it must come down. If it is born, then it must die. And that is where it comes in: the balance of life.
For the perpetuation of this species relies on the fundamentals of survival; the fit are defined as those who survive, and yet the condition to survive is to be fit. Therein exist conditions which test the population in ceaseless and incessant scenarios, so seemingly randomized yet so profound - and rare and therefore unprepared for - that understanding is often beyond our capacity, let alone acceptance.
For we are governed by hormones, the chemicals programmed to induce reaction, responsiveness, to perform this way dependent on stimuli. We are markedly made human by our ability to feel, emote, to communicate our sentience with a modicum of intelligence and emotion.
Logic then dictates that external stimuli of negative connotation, or perceived as such by our developed humanity, induces hormonal conditions to set in motion corresponding emotions: despair, disappointment, anger, despondence, remorse, resignation, fear, etc. These are such that can, in excess, tip the balance upon which our threshold for survival rests. It gives opportunity for us to reliquish our hold on our own health and well being; for us to be that much less careless about our safety; it means we are the weak -- and the weak are weeded out.
So keep in mind, when next you're sad, or struggling through hardship, wondering why. It's the test, the game, the way of life; hang tough, fight on, be strong. Survive.