The Universe is really big

I hardly see what your point is? No where did anyone say anything about afterlives or salvation or any of that. If for nothing else those selfish people should see the value that can be gained from a trillion untapped worlds.

I was connecting the "don't focus on your current life, but focus on the possibility of something being out there for you if you try to reach it" state of minds together. Even if we dumped everything we had into exploring out there, we most likely won't find anything of value in our lifetime. Tons of people don't like the idea of wasting everything they have now to benefit the future generations that they'll never interact with. We're just selfish like that.

We've got good reason to be selfish as well. We want what makes us happy above all else.