Evil is not simply a sum of certain drives and impulses but is the result of man's inability to separate himself from the corrupting effect of "knowing."
It is like the consequences of realizing that one can get away with a lie.
So long as–like in nature–it is inconceivable for a wrong action to succeed, there is no danger in multiplying knowledge.
But once man learns the power of untruth, that it is possible to satisfy his desire with a lie, this knowledge can be disastrous.
Evil in itself is therefore not dangerous.
It is the knowledge, the interiorizing of evil, that makes for corruption.
Just as some substances are injurious to the body and others can be swallowed without harm, evil is an indifferent substance for the angels but dangerous to man.
It is for this reason that God did not want man to eat of the Tree.
He wanted man to be holy and avoid the terrible inner struggle of sin, the historical chain of rising and falling.
–Rabbi Adin Steinsaltz
From In the Beginning by Rabbi Adin Steinsaltz