We all live in a box. We have to, at some level.
The fish in the aquarium lives in a box, just like the fish in the ocean. The box contains their life. Obviously, we prefer the ocean to the aquarium but, at some point, there are walls.
Make them big but remember we all live in a box, of some kind.
What you can never do, ever, is put God in the box with you. Or worse, in a smaller box.