The transition between faith to no faith.

[Mudhammam]

I'm reading Waking Up: A Guide to Spirituality Without Religion by Sam Harris at this very moment. I'd say there's a lot in there that you might find insightful regarding the context of your experiences.

I haven't read that yet, but one thing I find that differentiates me from many atheists is what I term "spiritual" -- which is the term I think I use when I'm trying to describe the connectedness I feel to the Universe at large.

The reality of that connectedness--that our "self" is in fact the sum of a conglomeration of environmental particularities--was perhaps best succinctly put by David Hume when he wrote, "I never can catch myself at any time without a perception, and never can observe anything but the perception."