The universe is vast. The Earth seems large, yet when examined on a cosmic scale, it is like a spec of dust, even less than a grain of dust. The sun itself is large enough to hold about one million Earths. And the sun is only an average star in a galaxy containing many, many stars in a universe of many, many galaxies.
If we stop to think about it, the vastness of the universe is amazing. While we go about our day-to-day business, we may think of the Earth as being the entire realm of reality. Yet this whole planet is like a spec of dust in the solar system. And the solar system is like a spec of dust when compared with the galaxy. And the galaxy—there are clusters of galaxies, and even superclusters.
The universe is undoubtedly large, almost beyond imagining. Yet, all this majestic expanse of galaxies, stars, and other celestial bodies, could not exist if certain values were not precisely what they are. There are many constants, such as the gravitational constant, that could be any value, yet they are the correct value for the universe to exist, and in some cases for life to exist.