Everyone can see it, there is something wrong with the world - the wickedness, the sorrow, the disasters etc. etc. Things should not be this way. This leads many people to conclude that God doesn't exist, but is that the sensible conclusion?
When I take my car to the mechanic and tell him there's something wrong with it I'm telling him it isn't behaving the way it is meant to, it's not doing what it was designed to do, something's not working the way the maker intended. It is only because I know that the car was designed and what it was designed for that I can say there's something wrong with it.
It is for that reason that it is nonsensical to say there's something wrong with the world and therefore God doesn't exist! We know there's something wrong with the world because we know there is a Creator and a purpose. When we see evil we know that's not the way we were intended to act. If someone wants to say there's no God then they have to give up their notion that there is something wrong with the world.