Thank you for your question. The problem of suffering is perhaps one of the most difficult questions that a Christian has to face, as it cuts to the core of our understanding of God and His purpose. Whilst some skeptics use it as an argument for atheism, I do not think this argument has the power to undermine the strong arguments for God’s existence. It does, however, warn us against naive understandings of God.
Before I begin to attempt an answer to this question it is important to distinguish two separate ways one might approach this problem. One is the intellectual perspective, i.e. how is suffering consistent with the existence of a loving God? The other is the emotional response to some particular instance of suffering. This second perspective is not one I can answer here, indeed it would be patronising to do so. Whilst an intellectual understanding of suffering might help someone put their personal suffering in a larger philosophical context, it will not remove their suffering or restore someone they’ve lost. Here I will only attempt to give some reflections on the intellectual problem of suffering.
The focus on child suffering is significant. One might ask why there is any suffering, whether experienced by a child or by an adult. I suspect there are two reasons why people often focus on the suffering of children. Firstly, it does seem unfair that some live to eighty or ninety in relative comfort, whilst some children die very young. We might feel, if not okay, at least less bad about someone dying at eighty or ninety. But if a child dies there is so much that they haven’t yet experienced or enjoyed – this seems terribly unfair. Secondly, we generally regard children as innocents. Even childish naughtiness is dwarfed by all the awful things adults get up to. So again, it seems unjust that innocents should suffer. The focus on child suffering takes us to the very heart of the general problem of suffering. We might accept some suffering that does us good in the long run (like going to the dentist); we might accept suffering that befalls wicked people (like criminal punishment); we might accept some suffering, as long as it is balanced out by a lot more joy. But we find it hard to accept suffering that seems pointless and random. If a child dies in an accident or has some horrible disease, there seems no rhyme or reason to that. How can a loving God allow that?
The first thing to consider is that we do not know all the purposes of God. We cannot know them because His thoughts are not our thoughts, and His ways are not our ways. We cannot know therefore that any particular instance of suffering is pointless. It is important not to misunderstand this idea. If a child dies it is glib, patronising and even hurtful to say “well, God moves in mysterious ways”. And one might justly ask “what way justifies the death of this child?”. The point is not that we should just accept suffering and not ask questions, but we do need consider that just because something appears pointless to us now does not mean that it is pointless in the grand purpose of God.
The second thing to consider is in what way do we expect God to prevent child suffering, particularly if we are inclined to accept some adult suffering. If a falling rock hits an adult they will die. If a falling rock hits a child they will die. Do we expect children to be immune to accident and disease until, say, their 18th birthday? How could you arrange such a world, and make the laws of nature behave in such a strange way? Could gravity not act on loose rocks above children? Or would children somehow be so much stronger than adults that they could withstand falling rocks? I do not mean these remarks to be flippant. I am simply asking the question: Is it possible to conceive of a world where adults suffering but children do not?
Now you might say, “I accept that the laws of nature mean that falling rocks will kill anybody unfortunate enough to be in their path but God could still intervene if he wanted to”. This is true, but let us understand what this entails. If we think that God should intervene to prevent the deaths of children then we commit to the view that every time a rock falls it will fall to the ground, except when there is a child in the way. In these cases, God would intervene to move the rock. (God would also have to intervene in lots of other cases too). Let us consider the implications of that. Firstly, the laws of nature would no longer be active, at least not in any consistent way. The law of gravity, for instance, would be a universal natural law except when it entailed the death of a child then it would fail. But not just the law of gravity – all the laws of nature would have to bend to prevent child suffering. So science, which depends on the regularity of natural laws, would no longer work and everything mankind has discovered by science would not have been discovered. Also these crazy laws might have unintended consequences. An avalanche headed towards a single child would automatically be diverted into some other course, perhaps into an adult (or even a village full of adults). Similarly, human free will would have to be overridden when it entailed human suffering. I might think that I want to drive at speed, or to ignore safety warnings, or to pollute the planet with green house gases. However, I would automatically be prevented from doing these things because it would entail human suffering. Worse than this, if a butterfly flapping its wings can cause hurricanes on the other side of the world then all my actions, however minor, would have to be minutely controlled by God otherwise I might unintentionally contribute to child suffering. My point is that to prevent all child-suffering would require that the laws of nature no longer function and that human free-will should no longer be operative.
(Now, this does not mean that God can never intervene, simply that when God intervenes there will be consequences and so He cannot intervene all the time).
The final consequence of God intervening to prevent all child suffering would be that His existence would never be in doubt. If anyone said “I don’t believe in God” then all that would be required would be for me to put a child in danger and watch as the child is miraculously saved. Now if God wants to His existence to be less than obvious, that is, if He wants people to come to Him through faith and love not through compulsion, then He cannot act in this way. His interventions have to be less regular to allow people to deny His existence, if they choose to.
There is one last point. We have seen that if we want to preserve the laws of nature and free-will then child suffering cannot be universally prevented. But this is only true if suffering exists at all. So one might ask: Why did God create a world in which suffering exists? Why not create a safe world without falling rocks, or horrible diseases, or nasty people? But that world you are describing is the Kingdom of God and if the world were already like that there would be no need for the Kingdom of God to come. But the Kingdom hasn’t yet come and we are reminded by the suffering around us that we need the Kingdom, when there will be no suffering. That Kingdom cannot exist whilst there are still people who are intent on doing wicked things. The Bible says that God subjected the world to futility (Rom 8:20) whilst there is wickedness on the earth. But there will come a day when God will judge the wicked and create “a new heavens and a new earth” for the righteous.