If earthly pain and suffering were purely a result of mal-intent – what we would call “evil” – what cause would there be for faith?
In the same way a man chooses not to jump from a cliff because the laws of nature tell him that he will die, the believer would cease to be just that – a “believer” – because there would be no reasoning to display faith. You see, if the world were governed by the laws of expectancy, we would worship God out of fear rather than faith, and this is to miss the point entirely. A man governed by the laws of gravity does not jump from a cliff [if he is of the right mind] because he does not want to die. In the same way, if nature taught us that all suffering is a result of human maliciousness, people would live good and loving, moral lives not out of love for God, but out of fear for pain. Thus pain must be inevitable in a certain sense, thanks to our fallen nature; this is why we are to “rejoice in our sufferings” – especially those horrid, inexplicable ones such as the death of a child or illness of even the godliest – because they allow us to display our faith that, even amidst the trials, our Lord’s plans are still to prosper. I think of David, and how his sin with Bathsheba resulted in the death of their firstborn. He mourned until the death of the child, but then after, he broke into praise! This was not an act of morbid fascination, but recognition that the Lord is in control and has the power to both give and take away. It could be argued that the death of this child was a result of the after-effects of human evil, but then I would retort that all pain is ultimately a result of evil to some extent – there would be no death or pain at all had we not eaten of that fruit in that garden so long ago.
To me, this argument fairly similarly reflects the reason why God does not blatantly reveal Himself to all of humanity – the Divine Secret, as I like to call it. One must not have ears to realize God, but the ability to hear; not eyes, but sight. If God made His presence visibly and undeniably known to all those alive (which He most certainly does, if only you are searching), we would worship Him out of fear rather than love, not like a bride to her lover or a son to his father, but as a prisoner to his jailor. God must leave us questioning both His existence and His omnibenevolence for the very same reason: He desires a relationship with us, not a religion. (And relationships are based on the foundation of love, which requires faith; if good things were guaranteed in a relationship, there would be no need for faith and therefore no evidence of love.) Faith provides us with true sight, and in this light of faith, all makes sense. It is not easier for the believer to make sense of suffering, but it is easier to rejoice amidst the pain.
Our God does not want us to love Him selfishly, out of desire purely for our own well-being (this is most directly realized through God’s portrayal as a Groom); He wants us to love Him for Him, recognizing that His plans are still to prosper and that He has not nor will He ever forget us – He is with us in both fire and flood. He is forever faithful and His love is as perfect as He – we have nothing to fear.