Finely-Tuned for Life
Physicists calculated that for life to exist, gravity and the other forces of nature needed to be just right or our universe couldn’t exist. Had the expansion rate been slightly weaker, gravity would have pulled all matter back into a “big crunch.”
We’re not talking about merely a one or two percent reduction in the universe’s expansion rate. Stephen Hawking writes, “If the rate of expansion one second after the big bang had been smaller by even one part in a hundred thousand million million, the universe would have re-collapsed before it ever reached its present size.” 
On the flip side, if the expansion rate had been a mere fraction greater than it was, galaxies, stars and planets could never have formed, and we wouldn’t be here.
And for life to exist, the conditions in our solar system and planet also need to be just right. For example, we all realize that without an atmosphere of oxygen, none of us would be able to breathe. And without oxygen, water couldn’t exist. Without water there would be no rainfall for our crops. Other elements such as hydrogen, nitrogen, sodium, carbon, calcium, and phosphorus are also essential for life.
But that alone is not all that is needed for life to exist. The size, temperature, relative proximity, and chemical makeup of our planet, sun, and moon also need to be just right. And there are dozens of other conditions that needed to be exquisitely fine-tuned or we wouldn’t be here to think about it. 
Scientists who believe in God may have expected such fine-tuning, but atheists and agnostics were unable to explain the remarkable “coincidences.” Theoretical physicist Stephen Hawking, an agnostic, writes, “The remarkable fact is that the values of these numbers seem to have been very finely adjusted to make possible the development of life.”