Why aren't people nihilists? [Spirituality & Religion]

Why isn't humanity full of nihilists? There is no solid proof that something will come after life. Eventually, the earth will be destroyed, the sun will die, and the universe will concede to its inevitable heat death. Humanity will destroy itself, and a feudal society will once again raise. There is hope for living, but there isn't really a point in a world that will die.