Of course the first problem that seems to come up when you question the idea of God is the meaning of life. People say, "Believe in God, because without God, life is meaningless."
That's not actually an argument; that life is meaningless might be undesirable, but that doesn't prove it untrue. But still, I understand: one still has to live. If you don't think God is out there, you have to find something else to believe in.
The trouble is that "what is the meaning of life" is a rather unclear question. Some people, when they ask it, mean, "Why am I here?" Others mean, "Why should I continue living?" or "What is the prime goal of my life?"
These are different. To answer the first question, it could just be chance. But just because there is no reason behind my existence doesn't mean my existence has to be meaningless.
Think of it this way. What is a lamp for? To give light. What is a tree for? To be a tree. Something made by people always has a purpose, but things not made by people just are. They might be useful, and they might not. You might want to sit under the tree, and that makes it useful even though it wasn't "meant" for sitting under.
I think that saying "what are people for" is narrowing people down to things. People don't have to be useful. Their existence is valuable even if it doesn't help anyone else. At the same time, people like to feel they are useful. It makes us feel valuable to know that we made a difference to someone. It can make the difference between having the strength to continue living in hard times, or feeling like we might as well give up.
It's easy to find the answer to this problem: all the people who love me, care about me, and rely on me are a reason to keep living. I matter to them. The more I have to offer the world, the more I matter. It's a good reason to offer more to the world -- to give more, and receive less.
Still, existential angst is a thing. A few months ago I was standing outside in my front yard, thinking, "What's the point? Life is full of suffering, and at some point it will be over. There has to be more than this."
Then I realized I was sitting under a perfectly blue sky, the sun was shining, a breeze was blowing, and my beautiful children were playing in the grass. And I thought: The very fact that I am here to enjoy this beautiful day is enough. Life has joy in it. The joy of looking at beauty, the satisfaction of helping a friend, the pleasure of eating a nice meal, the ecstasy of listening to a symphony, the pride of a job well done -- to have all these things given to me, even if it's by pure chance, makes me feel privileged. It's worth the discomfort and suffering and angst that life also includes.
I am thankful to be alive and I refuse to minimize that gift by pretending it's "just" a quirk of my brain, a random chance, a short moment in time. I was always taught that life is an eyeblink and eternity is long. That's a lie. Life is not an eyeblink, not to me, and what other perspective do I need to measure it against? This single day that I get the privilege of living -- if I pay attention and really savor it, it seems to last forever. If I thought it really would last forever, maybe I wouldn't bother savoring it. But since a day lasts a full twenty-four hours, and only twenty-four hours, it's just the right length to try to live to its fullest. If I am lucky enough to have more days, I will live those fully too.
My next thought was that not everyone's life is as happy as mine. Some people are depressed, some people are sick, some are starving or lonely. And so there comes part two of the meaning of life: to try to share the goodness of life with every person alive. I am so intensely privileged because of a thousand or a million actions others have done: my parents for bringing me into existence, the farmers who grow the food I eat, the person who invented the rhogam shot that allows me to have three healthy children instead of only dead children. On and on, all of humanity is an endless chain, or rather a more complicated network, in which we rely on each other and pass on the gift to the next generation. I resolve to do what I can to make it good for others. Comfort the afflicted, love the lonely, give to charity. I want to make some slight difference in the world that will make life better for others. It doesn't matter if they never know it. If I make the world just a tiny bit better, long after my name is forgotten, I will matter because I was a link in that endless chain.
That's the meaning of my life: to receive the gift that is life, to enjoy it, and to pass it on. It doesn't have to be the meaning of everyone's life; it isn't an authoritative answer. But it is a meaning that is worth getting up every morning to work on.
What is the meaning of your life?