All living things are part of the Universal One. Wherever there is life, there is One. You are part of the One, just as I am, and just as every other person, every cat, every dog, every ladybug, every tree, and every flower is. One way to think of it is this: when we are born, our bodies are formed of matter-energy, and our life is an aspect of the One which is extended into that body.
Just as we all come to life through the One, so we all return to the One in death. As part of the One, we share a common, if tenuous, link to a universal memory, which has in the past been referred to as Race Memory or a Universal Mind. On being reabsorbed into the One, we cease to exist as individuals, but some parts of us may endure. Strong memories or personality traits may endure, and may be part of the aspect of the One which makes up a new life. In this way, a sort of "reincarnation" is achieved. Some people, while still living, may also be able to access or contact these enduring parts of those who have gone before. This may provide an explanation for the phenomenon of "ghosts" or for contact with the dead.
Thus, while the individual is gone, we may also say that none of us are ever completely lost. Those we have loved and lost are, to some degree, always with us. Some may even live again. The old romantic notion of two souls bound for eternity, meeting again and again in life after life, might have some basis in fact.
As all life is One, it seems self-evident that all life is deserving of the same respect, and anything which is harmful or destructive toward life - any life - is an offense against all. This applies not only to the murder or harm of one of our own species, but to all. To destroy a tree for no reason, to kill an animal you do not need to eat, to torture a "game" fish for fun, to destroy an unborn life simply because it is inconvenient, or to harm or destroy a wildlife habitat, are all offenses against the One, and against all.
We have a responsibility toward our world, to protect and preserve our environment, not only for our own benefit, but for the benefit of all living things which also inhabit this planet. We have a responsibility to learn to live in harmony with our environment, doing as little damage as possible, and repairing such damage as we may be able. We have a responsibility toward all other living things, to treat them with respect, and to protect them to the best of our ability.
All of us share this responsibility, because all of us are One.