evil-doers
when Allah, exalted is He, and any of His Prophets say something it is not for us to argue or have our own opinion on the matter. when debating one has to know who is an atheist and who is a Christian, Jew, Muslims, etc., in order for us to know how to tackle the issue. obviously we cannot use the concept of God with an atheist because he/she will only mock and are full of disbelief.
as regard to the question you can have this line of thought from the earleist times and ask 'why did God allow Adam, pbuh, to eat from the tree?' or 'why did God allow satan, the cursed, to be evil and to mislead us?'
i think everybody is forgetting that there is heaven and there is hell and they lost all belief in these two realities. this world is all just one big test after another, only a test and nothing more. in Arabic world=dunya and dunya's root word is don which means 'lowly' or 'low', this is where the english word 'down' is derived. the Prophet Mohamed, pbuh, has said that this world is paradise for the unbelievers and a jail for the believers. also he said to live your short and temporary life in this world as if you are a stranger or a passer-by. in other words don't get too attached to anything, not your wealth, material things, not even your children. Everything on Earth will perish, EVERYTHING. The only reality is God.
peace to those who choose to follow guidance