This is actually the second time I tried to read this, and the first where I succeeded. Previously, I found the philosophical diatribes encouraging my mind to wander — which is ironic, given the context. This time, I enjoyed it. From first principles, what is spirituality? How do people around the world—with different and contradictory beliefs—have spiritual experiences? Where do feelings of "oneness" come from?
Harris explores spirituality building from observations that we can analyze ourselves. It isn't easy though: looking at the nature of consciousness is difficult, to say the least. And for my Western mind, adopting the illusion of self took self-exploration and observation, rather than through logical arguments. Read this if: you're interested in Buddhist ideas, but do not care for the dogma attached.