Yes, we are all one. I envision this to be like the vine in this photo. It reaches out and latches onto its surroundings. That way, as it secures itself to, say, a ledge or another plant, it is able to find the support it needs to continue to grow. It winds its way through the stand that it sits upon and creates beauty with its blossoms.
We are all tied together in one way or another. It is a matter of what sorts of ties we prefer. The toxic ties can be cut away, like a dying part of the vine. The healthy ties can be nurtured better once this is done because the energy of the plant can then go to the healthy ones instead of wasting its time trying to feed and carry the unhealthy ones. The healthier it becomes, the better it can breathe and send into the air that which other simbient creatures (humans and animals etc) need in order to breathe as well.
We are simbient partners with the plant kingdom. We exchange oxygen and carbon dioxide with each other and allow each other to live as a result. We feed on live plants to sustain our bodies. When we die, we get returned to the earth and as we decay we feed the plants in return. It doesn't even matter if we are embalmed, cremated, or just put in a box in the ground. Eventually we decompose and the plants are able to feed. When we become at peace with the fact that we are not on the top of the food chain, but merely a part of the food chain, we are able to show respect to our natural relations much better. Sounds morbid, this decaying stuff, but it is all a part of the cycle of life. This is why I give thanks to the plant kingdom, the "standing people" every day.