We Christians know that eventually, God will destroy the planet and replace it with a new Heaven and a new Earth. We, of course, will continue to exist for all time with God and Jesus.
Atheists believe that the universe is slowly and inexorably spreading out and cooling off, and that eventually it will suffer "heat death". All planets will be dead, all stars will burn out, and nothing will live.
So, when Christians write books and make music and build things, we do it knowing that we will influence current and future generations who will carry our ideas into Heaven for eternity. Atheists know that everything they create, no matter how beautiful or profound, will eventually cease to exist. Even a book popular for thousands of years, like Plato's Republic, will someday be forgotten; even if a copy survives for billions of years, locked in the frozen core of a dead world, there will be none to read it. Ever.
So what encourages atheists to get out of bed in the morning? And why do they all seem to worry about "endangered feces" and "historic preservation"?
I don't get it. At all.