Nice article! I had always thought that Christianity was my only motivation for caring about the outer world. After I de-converted, I was really confused to find that I still cared. I still wanted to donate to EA charities. This brought me some happiness, but after a lot of introspection, I was pretty sure that it would bring me more happiness if I donated only half of the money, and spent the other half of the money on a trip back to Guatemala to visit close friends. Even realizing this, though, I still didn't want to, and it boggled my mind...

Then I started learning about evolution and natural selection, that altruism is partially genetic, and it all cleared up a bit for me. I came to the conclusion that goodness can be an end in itself, just like happiness... and I wrote my first ever LW article about it here. It has a lot of the same ideas as yours but isn't so well focused.