Adam Frank in his blog post entitled "Life Is More Meaningful Than Mere Facts Can Convey" quoted Jean-Paul Sartre, ‘"Even if God did exist, that would change nothing."’ Adam’s point is that knowing whether God exists or not is irrelevant because life is about being. I disagree because knowing whether or not God exists determines the meaning of our lives. If God doesn’t exist then there is no objective meaning to our lives.
The philosopher, Arthur Schopenhauer wrote, “We can regard our life as a uselessly disturbing episode in the blissful repose of nothingness.” If God doesn’t exist then Schopenhauer is right, our lives are essentially meaningless. Since the material world is composed of parts it will eventually be torn apart via the second law of thermodynamics. Our bodies break down as we age making our lives ephemeral. Our own sun that makes life on earth possible is slowly dying. One day the sun will run out of fuel causing it to turn into a red giant. It will eventually expand and scorch the earth before contracting and going cold. The universe too is slowly dying. The universe is expanding at an increasingly fast rate so it is growing colder and darker. Eventually all the fuel in the universe will be used up and all the stars will die causing the universe to be extremely cold—all life would have been long extinguished. This means that all our memories and work in the physical world are doomed as well. Sadly, even the great works of Shakespeare, Plato, Tolstoy, Beethoven, Mozart, Da Vinci and Picasso will be destroyed. If there is no God then the world and humanity are like sandcastles built on the edge of the seashore and the great wave of time is poised to come crashing down.
If there is no God then we are only left with the illusory meaning found in atheist Existentialism; a meaning we fabricate and which dies with us. On the other hand, if God exists, God sparked the big bang and formed the universe so it would be amenable to highly evolved life so He could be in relationship with us. If God exists then the main purpose of our lives is be in relationship with God and glorify Him. Since God is eternal and spiritual He is not subject to the decay seen in the material world. The existence of God and the soul promises the possibility of our essence surviving forever. So, our money, fame and material projects will be destroyed, but all spiritual work will survive.
We can see that determining the existence of God has great implications for our lives. Without God there is no objective meaning in the world, as all of our essence, work and memories will be destroyed. If we can determine that God’s existence is probable then we can know that there is objective meaning and the hope of eternal life. Of course, if someone someday is able to prove that God doesn’t exist then that won’t take away the “being” that Adam is talking about, but it does mean that the wave of time is rushing to wipe it all away.