'Evil' is a manmade concept that comes from the dualistic thinking of the human ego. Categorical though creates pits opposites against each other as conflicting ideas that are unresolvable. If there is "good", then there must be "evil" ("light and dark", "life and death", etc.). It is a condition humans are born to, going back to the fall of Adam and Eve, which created the dualistic split between man and God. God is All-Powerful, without want or need to "create" anything, but is the 'Source' that allows all possibilities to arise.
In the East, duality is accepted and represented by the "yin and yang" forces of nature. The dynamic of polar extremes is cannot be reconciled, only transcended by what is called "non-duality" (or 'Advaita'). All opposites contain, and are define, partially, by it's counterpart. The further "east" you go, eventually you end up in the "west". In seeing opposites as "different", but not "separate" aspects of a greater whole, the dualistic point of view begins to break down, opening up more inclusive, rather than exclusive way of observing.
Inherently, everything is nameless and without description. The mind and ego's attempt to label and explain things creates imaginary boundaries of division, where what is viewed is dependent on one's dualistic positioning. There is no dualistic separation between a 'this' and 'that', 'here' and 'there', 'now' and 'then', outside of the mind's imagination. The ego projects our dualistic assumptions externally, which we tend take to have innate existence to reality and the universe.
"Fitting the square peg in the round hole", pretty much sums up the plight of the human condition, on the mortal plane of existence, when it comes to duality. It is what makes everything relative to everything else. "Good and evil", cannot be defined in absolute terms, and is determined by how you frame reality. Socrates believed that humans are born innately "good", and only choose what it believed to be "right", but do not always know what that is. To choose evil, even for it's own sake can only be done out of the belief that it is the "good and right" choice to make.
We might generally say what is, "good", is that which sustains and supports life, and that which does not is "bad". What we essentially mean by "evil" is that which perverts and distorts truth for personal gain, at the expense of the wellbeing and lives of others. Discerning the difference between "good and bad" is not always apparent, which is why humans use the assistance of thought and belief systems as a default for guidance. Otherwise, we typically determine "good and bad" by what is preferred and what is not.
God's role in "good and evil" can be seen as a 'Provider' of opportunity and possibility. Out of His Unconditional Love, it is God's Will that we have 'freewill', so that we may choose Him on our own, which demonstrates that He does not Rule by "force". Love that has to be forced is not love at all. The Lord made this world one of "variety" and "diversity", offering positivity, negativity, as well as neutrality, as available options to choose from, which is suitable for the capacity for freewill. All physical matter and energy is made of positive, negative, and neutral particle charges (protons, electrons and neutrons, respectively).
The more we choose the same as we have in the past, the more we reinforce the cycles, patterns and sequences of events in our lives. However, every instant is an opportunity to choose differently than we have before, altering the set of choices and possibilities available for selection. God does not interfere in our lives without our consent, or else it would be a violation of our freewill to choose for ourselves. God understands our limitations, and makes allowances for negativity, offering us the gift of freewill so that we may know 'He is the Way'.
The inclusive nature of 'non-duality', not only considers the duality of choosing 'this' or 'that', but also the 'choice not to choose'. Mankind's Great Spiritual Masters are examples of 'Surrender', at a deep and profound depth, to the dynamics of 'Divine Ordinance'. Great Teachers like, Jesus, The Buddha, Lord Krishna, chose to give up their freewill to 'Serve a Higher Purpose', greater than the sake of their own. Being without ego and sin, these figures are human examples for the way for the rest of humanity to follow in, if we choose to.
Had Adam and Eve, known better, they would had refused God's offer of freewill, trusting that The Lord Knows Best and Provides, and would had not been misled to commit "Original Sin". Both Christ and The Buddha, taught that 'sin' is another word for 'ignorance', and that it should be avoided. Humans are not born sinners because we're "wicked" and "evil", but because we don't know any better. If we did, we would. In order for freewill to involve choice, options must be present along with some degree of uncertainty of outcomes.
Any and all systems of high intelligence must operate on intrinsic laws of accountability. All actions and decisions must have consequences that are automatic, not arbitrary sentences casted down by God's "judgment". Outcomes are a result of the combined total of the past within present circumstances, rather than a ":magical" or "mysterious" force that "pops things into existence out of nowhere". To understand freewill properly, it is essential to understand the concept of "karma".
The Buddha said, "we are not punished 'for' our sins, we are punished 'by' them.". The Bible and Christianity do not have a specific term for it, but teach the concept of karma in the passages the mention, "an eye for an eye", and, "you reap what you sow." Jesus is quoted in Matthew 7:2, saying, "By the judgement you pass will be used to judge you, and by the measure you exact will be used to measure you." Even quantum physics reveals that our observation of the world influences what we see.
Adam and Eve made the misjudgment of seeing 'lack' in themselves, where there was none, in which they became motivated by 'gain'. Overcome by curiosity, they had already made the choice to inquire into "knowledge". "Biting into the apple/quince" was merely the catalyst that made the separation between "spiritual and material", an experiential possibility. Knowledge belongs to God, because only He can know all. God is 'All Knowing' by way of 'Being All', therefore, He is 'The Almighty'.
On our journey, we all must be tried and challenged, before proving worthy of advancing further. Because of ego, humans have difficulty getting past dualistic assumptions, and applying a non-dualistic approach. Humanity seems to only ever end up with answers that lead to more questions, because "knowledge only begets more knowledge to know", without end. God did not tell Adam and Eve His reason for not eating from the "tree" because it would violate their freewill to decide on their own.
Thus, it is said, "the wise only know that they know nothing", as Socrates confessed, remaining 'true to himself', nearing the end of his life. Einstein called it the "Theory of General Relativity", which is a fancy way of saying, "we know that we don't know". Science has only recently discovered what ancient civilizations had already known for thousands of years, without advanced theories, modern instruments and technology. Our universe has be describe as "holographic", where what is seen is dependent on the point of view. How we regard and frame our reality determines what is possible in it.