God hasn't allowed suffering. Man was the one that started it all - they need to find a solution to it. This is not Gods' problem, it's yours and mine
Actually, views on this very point are very wide ranging and some do not "let" God/Creator off the hook so easily.
If this world was created and regardless of cause, evil predominates, a Creator who lets it continue is as guilty as the evil doers.
If you had the power, could you knowingly "stand by" and allow children to be abused and killed? When would you step in and say, "Enough is enough". Saying that all humans are responsibile for evil undoubtedly has a grain of truth in it, but it is far from the whole truth.
Besides, even among humans, we endeavour to enforce laws on human conduct and convict, judge and sentence wrongdoers. The fact that the history of evil goes back millenia and continues into the present is a particularly difficult one for believers to explain away.
Among the smuggest explanations are those that assert God is somehow above all of this and should not be blamed. Hello?! I prefer to hold responsible those who have the power to stop it who chose not to. It is academic why it has continued; fact is, it has continued and if there is a Creator, the buck needs to stop there.
But I am a mere field mouse, easily squashed, so I better tred carefully (but it still doesn't satsifactorily answer the question - that is, if a Creator is "out there"...somewhere.