Wish we could Change the world

We wake up sometimes thinking how we wished we had the power to change a lot. If we were super heroes we would stop the crises in the Middle East, the terrorism in West Africa, recession in the western world and eradicate poverty and hunger.
We close our eyes so tight we imagine life was controlled by our wishes. Our good wishes. Then the world would be paradise, free from fear and death.
If only wishes were like prayers then we would have what we want. But why can't we pray as much as we wish? Is it because prayers need purity of heart to be answered? Or we are too scared of our wishes coming true?