The uncaring universe
We are alone in an uncaring universe. On the cosmic scale, we are even less than a pale blue dot, since, outside of a tiny region in just one of the billions of galaxies, we are too small to see. Our lives are much too short to see much more than a snapshot in the cosmic, geological, and evolutionary timescales. There is no consciousness hiding behind the cosmos, no greater being to love us. The universe had no purpose in mind when it created us, indeed it has no mind at all.
But just because the universe is uncaring doesn’t mean we have to be. We may be invisible from just a few light-years away, but we’re not a few light-years away—we’re right here. Our lives may be too short to see the universe unfold, but it is not too short to have plenty of experiences that are meaningful to us. There is no reason to identify with the universe’s apathy—we are not the universe. Unlike the universe, we have a mind and purpose.
When I say we have a purpose, I don't mean that there is an absolute purpose handed to us from above. We create our own purpose. This is true whether you believe in God or not. If God exists, you must still choose: is your purpose to do God's will, or to rebel against his will? The choice may be obvious, but it is you who chooses, not God. And that is not the only choice you make. Do you want to see the world? Help others? Develop talents? Better society? Make friendships? For the atheist, these choices remain the same. The only difference is that instead of choosing whether to do God's will, you choose whether to do good. This choice is equally obvious. After all, the only reason that doing God's will is obvious is because "God's will" is just a stand-in for what's good.
In the endgame, the Earth will burn up. Whatever good or bad humanity did would only cause an unnoticeable, irrelevant difference in the chemical make-up of the Earth. The universe will steadily continue on towards its death. Our souls will have long disappeared with our bodies rather than travel to any sort of afterlife realm. There is nothing to look forward to in the distant future. But why should we look so far in the future? If nothing that far in the future matters, then our only choice is to care about the present and near future. The present—your life, right now—is important. And since we care about others as well, this is reason to care about what happens to humanity after our own deaths.
Caring for others
If there is no afterlife in the end, what is the incentive to help others at our own expense? Well, if you're acquainted with game theory, you know that helping others often results in your own benefit in the long run. If you're acquainted with the theory of evolution, you know that social creatures like ourselves adapt by coming to want to help others. If you're acquainted with friendship, you know that helping others is its own reward. My preferred reason is because helping others is, well, helpful to others. It's not for me, it's for them. Aren't they reason enough?On the lighter side, it's a juxtaposition of Dawkins and dinosaurs, as presented by Dinosaur Comics! Enjoy life!