The unity of all the universe is one of the greatest truths that people need to realize is to become one with God. Take for example a large oak tree. There are branches moving this way and that, there are nuts that are falling off all the time. There are leaves that are blowing everywhere. But at the core, you know that there is just one tree there, at the core. Deep down, we are all part of one large tree. When you are miserable you are separate.
When you really know you are one with the universe, you are happy. But your ego prevents you from being happy. If you are happy and at one with the universe and one with the present moment (neutral to the ups and the downs), then the ego disappears, along with your unhappiness. The very word ego means how a person feels as separate from others. The whole universe itself is God in a way of thinking. If you edge out the Universe, it is like a drop of water on a waterfall which still thinks it is separate from the water that went over the edge of the falls. No, the drop of water is part of the river that with which it will eventually rejoin when it hits the bottom of the waterfall. The drop of water will continue on and become part of the river. It will again be ONE with the river. Then, if the drop of water realizes it, it will notice that was always part of the body of water to begin with. In a way, you always were, you were never born nor will you ever die. You were just momentarily separated from the whole of the river.
Like a child before birth, the individual was part of the universe and the river, then at birth, it separated out like a drop of water from a river that became a waterfall. Our lives are like we are a drop of water as it separates from the river and becomes part of the waterfall. There are millions of droplets of water falling together in the waterfall, each one separate—but really coming from the same source. At the bottom of the waterfall, it will rejoin the Oneness from which it came. The droplet will cease to be separate.
If the water droplet sees itself separate from the millions of other water droplets that comprise the waterfall, then it metaphorically speaking can suffer. Once it realizes that it is merely part of the waterfall which is part of the river, which will eventually become part of the ocean, all suffering and attachment will stop, and thus will the suffering stop.