Life after death?

[Whateverist]

The world at large apparently begins and ends with the world of people. That strikes me as a little narrow.

If you are using the term 'world', I think it does specifically refer to our planet.
Are we a bunch of relatively intelligent carbon units in a potentially infinite universe? Yes.
But that doesn't mean that the human community should be any less valuable to humans, at least. I don't think a human being can have greater achievement beyond helping other people.

I wasn't thinking of anything extraterrestrial. We are one of many creatures on this very same planet. Like them we are DNA replicating mortal creatures with instincts bent on our own survival and like many of them we owe our success to our capacity for cooperation and the ability to place the good of the whole above our own

I don't think we need to devalue human community. I doubt we have that choice. However, if the peculiarities of our development really do make us exceptional, perhaps we should have a greater regard for the web of life of which we are part. This short sightedness in regard to non-humanity isn't unique to Christians or theists more generally. But it is pretty prevalent.