In Buddhism, we distinguish between spiritual experiences and spiritual realizations. Spiritual experiences are usually more vivid and intense than realizations because they are generally accompanied by physiological and psychological changes. Realizations, on the other hand, may be felt, but the experience is less pronounced. Realization is about acquiring insight. Therefore, while realizations arise out of our spiritual experiences, they are not identical to them. Spiritual realizations are considered vastly more important because they cannot fluctuate.
The distinction between spiritual experiences and realizations is continually emphasized in Buddhist thought. If we avoid excessively fixating on our experiences, we will be under less stress in our practice. Without that stress, we will be better able to cope with whatever arises, the possibility of suffering from psychic disturbances will be greatly reduced, and we will notice a significant shift in the fundamental texture of our experience.
James: When I first started practicing the Dharma and meditation in particular I would have these spiritual experiences such as a feeling as though I was floating while meditating. I have had amazingly vivid and seemingly real dreams of being visited by great Buddhist teachers during deep contemplation while sitting. However, in my opinion they are like empty calories in the long run of my practice. It's like eating a gooey, sugary treat while hiking, which gives me an explosion of tasty pleasure but in the long run it is empty of the kind of energy needed for sustained progress along the path. If I indulge in these sugary treats too much then I get a stomach ache and realize that the special treats if indulged in too much can cause more suffering than benefit.
Spiritual experiences like moments where visions of enlightenment break through my ego-mind barriers and tempt me to obsess over them like a sugary but empty food. They are shiny objects for the ego-mind to latch onto and use to claim some sort of exceptionalism, which (I have found in my personal experience) is a result of placing too much importance to these experiences
When I have had spiritual experiences they are quick bursts of exciting phenomena experienced while meditating that explode into my mind like a bright comet, which enthrall me but burn out quickly. I find, however, that realizations are rare but that they, unlike a comet are like earthquakes that shift, shatter and altar my life forever. For example, it was nice, entertaining and tantalizing to feel so at one with things while meditating that it felt like my body was blurred and blended into the surroundings like I was the subject of an artist's painting. Whenever I feel this, it always makes me happy but is nothing like actually realizing (and thus seeing) emptiness in all things and places without having to induce it through deep meditation.
~Peace to all beings~