The following is an excerpt from one of the free articles available on www.endless-satsang.com entitled What is Advaita or Nonduality?
What about your experience right now? Is it possible to discover this subtle oneness in ordinary experience? It is, if you set aside the expectation of a dramatic experience of oneness and explore the oneness a little bit at a time. Just as even a single drop of water is wet, you can experience oneness in even simple everyday experiences, since oneness is a fundamental quality of everything that exists.
As an experiment, just notice your fingers and the palm of your hand. Can you really say where one starts and the other ends, or are they one thing? To take this further, where does your hand stop and your forearm begin? Can you experience the oneness of your hand and your forearm?
If these are not separate, then what about all the other parts of your body? Are your feet and your ears really one even though they are so different? Now notice if there really is a separation between your thoughts and your head. Where does your head stop and something else called thought begin? What about feelings or desires? Are they really separate from you or your body?
Now, notice the simple sensations you are having: the sounds you are hearing, the sensations of touch, and the objects and events you are seeing. If you are seeing, something, where does the seeing stop and something else called the eye begin? If you are hearing sounds where does the sound start and the ear stop? Perhaps the hearing and the sound and your ear are all one thing. Yes, the ear is different from the sound, but in the act of hearing they become one thing.
Then, where does the source of the sound stop and the sound itself start? For example, if a bird is singing outside your window, where does the bird stop and the sound of its song begin? Or are they one thing? If the bird and its song are one thing, and your hearing and the song are really one thing, then is it possible that you and the bird are one thing also?
Advaita, or oneness of Being, has often been thought of as something hidden or difficult to experience, when it is quite ordinary and available in every moment. Of course a big experience of oneness, where you directly experience the oneness of everything, is a rare and dramatic event. But why wait for something so rare when this sweet and satisfying oneness is right here, right now?