Symbolism is Universal
We are biologically identical to our ancestors
There are things in our environment that trigger certain responses.
The innate fear of snakes, spiders, and the like is embedded in our genes.
Our ancestors evolved in specific environments, which were for the most part savannas and jungles.
Picture the rat-like ancestor who lived in trees.
Even after that we still lived in similar environments for a long period of time (hunter-gatherer lifestyle).
Snakes
Probably one of our greatest fears was that of snakes, for they were hidden in between the leaves and around the branches of trees, camouflaged until it was too late.
One can imagine the fear, the surprise, the instant reaction to an evil lurking in the shadows.
Hence the snake has a very specific symbolic connotation:
It is the man facing the unknown, conquering fear in order to expand territory, and the virgin symbolizes the reward : procreation, prosperity.
It is a formula for the hero.
The snake is also present in Nordic mythology.
Thor fighting the world-devouring Jörmungandr
The same goes for the symbolism of the following the tree1 and water (which also symbolizes chaos).
Here it becomes even more apparent because of the water :
Also at the Louvre
In fact, all myth communicates truth symbolically because we can understand it through the symbols.
Note that the snake will never symbolize fertility or "light", something arbitrary.
This fact alone refutes all claim that the Bible has arbitrary power over others.
If a priest uses it in such a manner it is only pointing toward his own ignorance of the deep symbolism present in it.
Symbolism is not arbitrary. Symbolism is universal.
Symbols have specific, organically predetermined meanings to humans, for our biology remains largely the same as our ancestor's.
Ygdrasil is the basis for reality in nordic mythology.