Advaita Vedanta literally means non duality. The concept of Advaita Vedanta is far deeper than its literal interpretation. In Advaita Vedanta, we never say it is one, we always say that it is non-dual. This has great significance. It states that there are no two things. It is the philosophy of oneness.
Godliness is not anywhere outside, but within you. According to Advaita Vedanta, there is nothing and no one which is as close to you than your own self. It is the nearest door to divinity. Outwardly, we may seem to be different, but inwardly, we are all in unison and tied with an invisible thread. This is what Advaita Vedanta is. Know your own self; this realization opens the door to all that is within and beyond.
When you see a leaf, it may appear to be a single leaf outwardly, but if you could penetrate deep within, you would reach the point from where all the leaves emanated in unison. You would reach the source. Similarly, one who enters within simultaneously knows all.
The distinction between you and I disappears at the moment self-realization dawns upon an individual. With the knowledge of Advaita Vedanta, the feeling of being a separate entity fades. As a tree is not made of a single leaf, nor are we complete in ourselves. A tree is much more than just a bunch of leaves and so are we, much more than what we see outwardly.
Advaita Vedanta is an immensely strengthening and ennobling path. It states that we are the highest power possible and everything lies within us. It is a matter of intense self-realization. Spiritual awakening brings us consciousness, which ultimately brings us to the spiritual awareness of the self and its strength. Being in communion with the totality of the universe is the main purpose and meaning of Advaita Vedanta. It emphasizes merging our soul with the Ultimate Consciousness. We achieve the final goal when that merger occurs. God reigns in all of His manifestations and we, being one of His major creations, are linked to Him by an invisible thread. A creation cannot be substantially different from its creator. The harmony between the two is Advaita Vedanta.