I got a call from a friend telling me that another really good friend's wife has just been diagnosed with cancer all through her body. It is one of those cases where I have to wonder, "Why?" and "Where is the fairness in this life?" as this lady was tops in my book, just a real genuine good person.
Ultimately the answer is that long ago, mankind makes a wreck of God's creation by opening the flood gates to sin (Genesis 3). The consequence was that death and destruction entered the world. "In the sweat of your face you shall eat bread till you return to the ground, for out of it you were taken; for dust you are, and to dust you shall return" (Genesis 3:19). God had warned Adam and Eve that this would happen, but they sinned anyway.
Fair? This world won't ever be fair. It has taken too much damage. "I returned and saw under the sun that -- the race is not to the swift, nor the battle to the strong, nor bread to the wise, nor riches to men of understanding, nor favor to men of skill; but time and chance happen to them all. For man also does not know his time: like fish taken in a cruel net, like birds caught in a snare, so the sons of men are snared in an evil time, when it falls suddenly upon them" (Ecclesiastes 9:11-12).
Your despair comes from only seeing this life. "If in this life only we have hope in Christ, we are of all men the most pitiable" (I Corinthians 15:19). This world is destined for destruction and our eye should be fixed on the world that follows (II Peter 3:10-13). "And I heard a loud voice from heaven saying, "Behold, the tabernacle of God is with men, and He will dwell with them, and they shall be His people. God Himself will be with them and be their God. "And God will wipe away every tear from their eyes; there shall be no more death, nor sorrow, nor crying. There shall be no more pain, for the former things have passed away"" (Revelation 21:3-4).
Knowing that we can be a part of a better world, we do all that we can to be found pleasing in His sight.