I'm not sure, but I think this question is about what is generally known as Olbers's paradox: If, at any given moment, light from all light sources in the Universe are illuminating any given point, one might expect every point to be extremely bright.
To be precise, consider all of the light sources in a spherical shell of radius $R$ and thickness $dR$. If the Universe is uniform, the number of such sources is proportional to $R^2\,dR$. The apparent brightness of each source is proportional to $1/R^2$, so the total light striking your hand from all such sources is simply proportional to $dR$. If the Univers is infinite, then the total that results from integrating all such sources is infinite.
In reality, distant sources will be blocked by nearby sources, so the power striking your hand won't be infinite, but it will be as large as f the entire sky were filled with sources of the same temperature as a typical star. (To see this, note that every line of sight ends on the surface of a star. The surface brightness (watts per steradian) due to a source doesn't depend on distance: the brightness goes down like $1/R^2$, but so does the solid angle. So the entire sky has the surface brightness of a star.
That's the paradox. What's the resolution?
The main thing is simply that we shouldn't integrate out to $R=\infty$. The Universe has a finite age, which means we can see out only to a finite distance. If you consider only the sources within our observable volume, the integrated brightness of all those galaxies still turns out to be very small. Galaxies are luminous, but they're far away. (There's also the fact that distant sources are receding from us, so the light from them is highly redshifted.)