The original druids believed in reincarnation.
That is the belief where when one dies, one's body decomposes, but is reborn in another body.
So then everyone has lived before and will live again.
One may have been a bird in a past life, and one may be a mite or a carrot in a future life. Some tribes avoid eating certain animals because they believe that the souls of their ancestors dwell in those animals. A man could become his child if he dies before the childs birthday.

In those ancient religions, reincarnation was not a good thing.
To achieve the state of ultimate bliss one had to escape from the cycle, and rebirthing of the awareness, by entering a new animal body was downgrading to the soul.

In New Age religions, being born again seems to be a kind of perverse goal, and the training of the self to prepare in this life for advancement in the next.

So when JohnSA added “that whilst science and religion are very similar in the early stages, they tend to differ when they comes to adolescence”, and religion tends to continue to rely upon faith”

Remember that the separation in human considerations are still bound together in all civilizations from the most primitive tribes separated from a pee-line to many thousands of miles. Some form of supernatural religion is still present, and accounted for.
All have a religious activity of some kind whether there is a god/God/goddess/ or some other form of animal. or demonic character.

So then the common ingredient is as longtrek has observed with “The key to understanding both is understanding human nature” I agree, and point out that it is true when the dialogue is pre-Biblical, Christianity.

When the Bible became the only true stepping stone in the stream.
That left no other stone to jump to for Christian believers.
It does not deviate from human nature for it is human nature for humans to want to be accepted by the societies they exist in, and having the same religion goes with the grain while different belief systems cut across, and abrasions form.

Modern science has broken the traditions of early scientific endeavors by preaching separation of science, and religion.
So then science has changed, as has religion.

Today science, and religion exist, peacefully, only in countries of one religion, and that religion dominates all science.
Be it someone’s enthusiasms, or fanaticism. It can be counter productive, as Phill questions, but it is still a dominating human condition.
Seemingly impossible to eliminate where the dominating religion requires obedience to it’s philosophy, and controls the society under it’s domain.

Of course the connections, Caelia, are human inventions, and to most humans this is evidently the case, as most will not argue otherwise.

But to respond to your question concerning great distances between two tribes
Written indications have shone that all human tribes have religions, and do/did practice faith to the dominate tribal religion.
Also! Science is present in some form due to human needs prevailing to the human situations at the distant locations

Of course finding established Christianity present in it’s original form would be an exception, and the exception is due to having a book designated as the ultimate, and only stepping stone.
This one book idea is instrumental to the spreading of one philosophy in much the same way that certain chains of businesses become established world wide.
Coke being the one that comes to my mind… while coke is not everywhere, neither is Christianity!

But Jesus was a friend of mine! :box

(note) ---This post edited to appease Caelia's well taken point expressed in a post below---Sorry Caelia! :(