Philip Pullman's His Dark Materials series consists of three books. The one I like best is The Amber Spyglass, because it's toward the end of that book that he becomes most philosophical.
In chapter 34, there's a night when Mary can't sleep. She goes outside and watches the clouds, the trees, and the Dust. Dust is a concept that exists throughout the three books. I think that it represents life force, free will, creativity, love, consciousness.
When Mary went outside, "She turned toward the grove where her climbing tree stood. It was twenty minutes' walk away; she could see it clearly, towering high and tossing its great head in a dialogue with the urgent wind. They had things to say, and she couldn't hear them. She hurried toward it, moved by the excitement of the night, and desperate to join in. This was the very thing she'd told Will about when he asked if she missed God: it was the sense that the whole universe was alive, and that everything was connected to everything else by threads of meaning" (p. 449).
To me, this is a description of pantheism: There is no all-powerful being controlling the world, but there is a sense of magic and connectedness in the universe, which people can feel when they are out in nature.
As she continues to watch, Mary realizes that dust is flowing out of the universe, being lost to entropy, and she sees that the wind, clouds, moon, and trees are trying to hold it back. And she found that that was her mission too, to try to increase Dust rather than decrease it.
Then Will and Lyra fall in love, and a thick cloud of Dust is drawn to them. This fits with what I was just writing with regard to Blood Brothers: that the way to serve God (or Dust, as the case may be) is through God's creatures, through treating others with love.
Will recalls what his father told them: "He said we have to build the Republic of Heaven where we are. He said that for us there isn't anywhere else" (p. 488). I remember my grandmother saying that Quakers, Unitarian Universalists, and another group, maybe Jews, get along well because they tend to focus on the present world rather than on how to get into Heaven for the afterlife. That's what I believe too. There is no afterlife. As he said, "we have to build the Republic of Heaven where we are." And we build it by doing things that grow the Dust, we build it by building a world where people treat each other with compassion and integrity.
Lyra was able to read the alethiometer until she and Will fell in love. Then she was no longer a child, so she lost the ability. Xaphania tells her that as a child, she was able to read it through grace, but she'll be able to read it again with a lifetime of study. "Your reading will be even better then, after a lifetime of thought and effort, because it will come from conscious understanding. Grace attained like that is deeper and fuller than grace that comes freely" (p. 491). That is what I think about getting older. Although there is the danger of becoming jaded and bitter, if we open ourselves to learning, life becomes deeper and fuller.
Xaphania tells Will and Lyra, "Dust is not a constant. There's not a fixed quantity that has always been the same. Conscious beings make Dust -- they renew it all the time, by thinking and feeling and reflecting, by gaining wisdom and passing it on. And if you help everyone else in your worlds to do that, by helping them to learn and understand about themselves and each other and the way everything works, and by showing them how to be kind instead of cruel, and patient instead of hasty, and cheerful instead of surly, and above all, how to keep their minds open and free and curious..." (pp. 491-492).
The book ends with Lyra saying, "We would have gone with Will and Kirjava....But then we wouldn't have been able to build it. No one can if they put themselves first. We have to be all those difficult things like cheerful and kind and curious and patient, and we've got to study and think and work hard, all of us, in all our different worlds, and then we'll build....the Republic of Heaven" (p. 518).