This from an old Zen saying...
“Heaven and earth and I are of the same root,
the ten-thousand things and I are of one substance.”
The ten thousand things is a reference to the universe, to all life, all existence as being of one creation. Historically, Monotheists would have disparaged such a claim suggesting God made everything but the word God is a man-made thing. Once you give something a name it no longer is the thing it was. God is a word as is deity. It is possible to know God without recognizing God the deity. Another word that could easily replace God is Tao. Again, Tao is but a word, another man-made word.
When you meditate or even when mindful, that which some call God is with you. The eternal and the external are fused as one. You and the nameless, that which is greater than you yet of which you are a part of, a child of the universe, breathe as one, become as one for that is how life is - one.
Life exists within and without us. It exists in a myriad of amazing forms yet, when you look deep into any organism, breaking it down to fundamentals, all existence is made up of the same stuff. Hydrogen, the most plentiful substance in the world, carbon, nitrogen and oxygen and many other elements. Earth and its lifeforms all contain these linked parts. If there was life on Mars many eons ago then that too would have comprised the same basic elements. If there is a planet or planets out there, and mathematics suggests the likelihood high, then whatever life lives on those planets, be they newly evolved or thousands of years older than ourselves, then they too are part of the ten thousand things.
Science is nothing more than a tool by which we understand ourselves, our planet, the galaxies where our planet and others spin. The connection once proclaimed by Eastern philosophies is now accepted by Western science, by science in general. All life is linked. Nothing that lives exists without those elements we know of. If there are Aliens visiting our homeworld then they too are part of the ten thousand things.
Humankind likes its labels. As a species, we think in linear terms, we apply convenient names and tags to everything. Life though isn't like that. Life is not linear but rather resembles a Rorschach - a great big splodge. Humankind separates sexual drives. They would have us believe in Heterosexuals, Homosexuals, Asexuals, and a variety of other sexuals. All there is are people with different tastes. Humankind breeds division. Racial, sexual, class, religious, political, national and of course, Extra-Terrestrial. Division is the cause of much hurt, much harm. Wars have been fought over territory, over borders. Borders, like time, are a man-made construct, they don't exist. Simply ask fish or birds or contagions or the tide that rides the humble oceans who lap at our shores.
This planet, this Earth, is not our planet. We are of this planet. This Earth is of the universe therefore so are we, so are Aliens.
The word Alien defines a being, not of this planet, not of this earth but from some far off other-world therefore not like 'us'. As we have learned all life is connected. Aliens are in reality nothing more than another variety of life brought into being by the same energy, the same Chi as the Chinese would suggest, the same force as were we. There are no aliens only other beings like us, like cetaceans, like millipedes, like crustaceans, like mammals, like grass.
“Heaven and earth and I are of the same root,
the ten-thousand things and I and Aliens are of one substance.”