I hear this question again and again – often from Christian friends who have been confronted with some version of it by a son or daughter, sibling or spouse, friend or parent, and don't know how to respond.
The Bible, of course, provides many possible reasons. For instance, Hebrews 12:3-11 gives us plenty to chew on. Consider the conclusion of this passage: “Now no chastening seems to be joyful for the present, but painful; nevertheless, afterward it yields the peaceable fruit of righteousness to those who have been trained by it.” That verse alone should often be enough to satisfy sincere questioners, particularly when examined in the light of Romans 8:28: “And we know that all things work together for good to those who love God, to those who are the called according to His purpose.”
Alas, there are many who simply dismiss what Scripture has to say about any subject. I know; I was one of them until the Lord softened my heart with sorrow.
In such cases, perhaps a secular story would be more helpful. Christian apologist Ravi Zacharias shared an excellent tale in one of his riveting university Q&A sessions. Based on mideastern folklore, the story went something like this:
A man’s horse ran away. His neighbor came to him and said, “Bad luck that your horse has run away.”
The man said, “What do I know of these things?”
But a week later, the horse came back, with 20 wild horses in his wake.
The neighbor said, “Good luck – you now have many more horses.”
The man said, “What do I know about it?”
Trying to tame one of the new horses, the man's son was kicked, and his leg was broken.
The neighbor said, “Bad luck, your son’s leg being broken.”
The man said, “What do I know about good luck and bad luck?”
A few days later a bunch of thugs came by in search of able-bodied young men for their gang. They were about to kidnap the man's son. But when they found out that his leg was broken, they left him behind and moved on to the next house.
The neighbor said, “What good luck that your son’s leg is broken!”
With this one little series of events, Ravi reminded his listeners that we do not know what lies ahead. Instead of denying God’s goodness (or his very existence) because He failed to live up to our little ideas of right and wrong, we would be wise to wait until we stand before Him, face to face. Then, if we still care about such things, we can ask Him to explain Himself. We will no doubt learn that, in every case, He had perfect reasons for doing, or failing to do, what we expect of “a good God.”