Humans are responsible for their own actions. The whole "free will" and "God has a plan" ideas are very hazy - they have little scriptual backing and frankly the latter promotes a lack of responsibility.
But the answer is multi-pronged, it depends on what you believe God to be, or not to be. Whether that God has a direct affect on the world, controlling everyone much like a puppet master, or a more distant God, setting things in motion and watching things unfold or somewhere in between.
Personally? I go with ourselves being the main perpetrators of suffering - to deny responsibility for what we have done, are doing and no doubt will do, is a crime in itself. When it comes to natural disasters, I feel (God or no God) that they are simply that. Natural. Things happen. Build a city on a faultline? Expect Earthquakes. Just as an example.
There are plenty of paths to go down, explore what you believe. Perhaps using other belief systems as a starting point/counter-point. "Buddhists believe that xxxx, unlike Christians who believe that xxxx, I feel, however, that xxxx". That'll give you some historical ground to start from. (assuming you're actually going to write an answer, or something similar appears in your actual exam)
Because almost 80% of world population is religious and it is good rounding and hopefully will stop, the total irrational hatred of religion.
There are plenty of rational reasons to be against religion. To say otherwise is illogical. Both Atheism and Religion are extremist.