Bigger Than You Can Imagine
I bet you I can think of something bigger than whatever you can think of (and your thing can't be God or the Universe). It's probably not THE biggest thing out there, but it's the biggest thing humans have found thus far:
Giant Amoeba-Like Blob From Outer Space. It's 200 million light years wide. It actually contains a bunch of galaxies and lots and lots of gas. A light year is the distance light would travel in one year (light is the fastest moving thing we really know about). You could also use "Parsecs", which is 3.3 light years.
Anyway, that blob is mind bogglingly enormous. It reminds me of the not-all-that-uncommon concept that heaven/hell might actually be somewhere out in space. Ridiculous? Maybe. The scary movie
Event Horizon basically found an alternate dimension in outer space which turned out to be Hell. It's a remnant of times long ago, but people commonly look up at the skys when they are referring to heaven. It's just like the search for the Garden of Eden or the search for Atlantis. In that same way scientists are searching for the "center of the universe", or the starting point. Since the universe appears to be ever expanding, perhaps it all started expanding from a single point (goes along with the whole Big Bang Theory).
Anyway, there's some side thought that twists that idea around to be that the so-called center of the universe is the physical location of heaven. Do I believe this? Nope. But it's a pretty fun concept to entertain. What if we could find some sort of special location where physics/time behaved differently or some long lost alien civilization. I know it's not out there, but I guess I just like to imagine it could.