The Kabballah Tree of Life is basically a skilltree, similar to the chakra system. each of the circles references a "skill" or concept to be unlocked which the each influence another based on how a point is skilled. To unlock the next you must unlock the one before starting at the bottom. You can take the left or the right path or at the optimum a balanced one. left and right are opposed to another, they are represented by the 2 pillars in freemasonry, Boaz and Jachin and symbolize the duality of this world. good and evil, light and dark, strength and beauty, and supposedly you can achive godhood/God by reaching the top. Now this is very important: You cant.
Kabballist or gnostics usually try to push moral relativity. For example where gnostics say "All is one, one is all, thus God is also evil and i can find him through that just as i can find him through good" or through "God is merely a ruleset, the laws of nature and has no will, thus there is no absolute authority there saying what is good and evil and thus my definition is as good as the next one". Similary Kabbalists try to argue you need to do both, good and evil to find the middle path that leads right to God.
Lets look what the serpent baited Eve with
5“For God knows that in the day you eat of it, your eyes will be opened and you will be like God, knowing good and evil.”
you will be like God
Godhood through works/knowledge, and look where this brought us to. The only way Gnosis/knowledge leads to Godhood/salvation is by realizing that there is one true God and that only he can save you, and that this is Jesus Christ. All roads lead to rome and as such all logic leads to God.
A good way to explain it is the Chakrasystem which seems to be a somewhat simplified version.
The root chakra is your survival instincts. only if you rose above the constant fear of death you are able to actually process new experiences and evaluate them, see them from all angles outside of the threat they pose (sacral chakra), after that comes the solar plexus chakra responsible for our self esteem and self worth for which we have to see us in context of the new experiences and how we handle those. only once you love and value yourself you can start loving others (heart chakra), and love goes through the stomach, solar plexus>heart. next comes the throat chakra and the best speaches are those done by talking from your heart, what you truely care about and communication is the job of the throat chakra. Once you can formulate the truth properly there comes understanding and insight, the third eye chakra, and from this understanding you realize that everything is connected with another, the crown chakra
by putting you in a constant state of fear and anxiety they lock you in the lowest state of conciousness, occupied only with survival unable to really process any experiences. Early traumata like circumcission can alter your brain enough to effect your entire life.
All the fear propaganda all around merely is there to lock you into the lowest state of conciousness controlled by fear.
There is also the reptillian brain in charge of pretty much the same as the root chakra, survival instinct. Some people are "entirely" controlled by this area in the brain with every act only being there for survival. Stealing money from some guy, or even murdering people that threaten your lifestyle. The temptations of the flesh. The abuse and sodomy affecting the lowest chakra which is the easiest effected (iE through sodomy) due to its connection with the material.
The Serpent is a common symbol for evil because just as this chakra and conciousness is the lowest so is the snake crawling at the lowest on the ground representing the conciousness of the individual