Light Direction

I have a room and i want to put a light to come from the top of the room.

but all what i tried seems to have no effect. I always have a light that point from some direction to another (only one side of a room is bright, the other is dark).

Spotlight also doesn't have any effect.

please help

Try up-ing the ambient light, then the dark won't be as dark. Or you could add another light?