This is no doubt a question many of us have had, and most have no answer to. But after mulling it over, the answer seems quite simple: Because Free Will exists. Now, before i can explain why, let us break this down practically. At the primal level, what is Free Will? The ability to choose for one's self. However there is no Free Will if a Choice has no impact. For example, if you were asked to pick a color for something, but no matter what you pick has no impact whatsoever, not on you, the object, nor those around you, and does not influence anything for good or ill even in the most minute of ways, not even in the way or reasoning for why you picked it, not even for "just because i felt like it", then it is not truly Free Will, but merely a facade. To simplify this, if all choices you have available are all neutral, and lead the same path the same way, then you aren't really choosing. A Choice must have impact in order for it to identify as an act of free will, even if that choice is to not act.
However in order for a Choice to have impact, it must have favorable and less favorable outcomes, regardless of how minute. From the first Favorable Outcome comes the beginnings of the Concept of Good, and the Less Favorable Outcome grows over time as more are decided into the Concept of Wrong. Wrong itself isn't evil, however as many varying unfavorable ways and events come to be labled as Wrong, as Wrong grows as a concept, thus comes the beginning of the Concept of Evil. Simply by making the act of Choosing, with the choice having impact, the natural order of the universe. As more choices are made, so do both Concepts of Good and Evil. Neither exist with out Free Will.
It is known by many Christians and Jews that God gave mankind one gift to stand out from the animals, and that was Free Will. Free Will empowers Choice, and Choice begats the concepts of Good and Evil, Order and Chaos. You cannot have Good and Evil without Free Will, and you cannot have Free Will that does not begat these concepts, else you have no Free Will.
This Analysis does not make Evil good nor okay. Evil is still Evil. Nor does this Analysis support the idea of ridding Evil by ridding the world of Free Will, as that is incorrect as well.
The Time before Free Will was not Evil, for there was no such thing, no oppressions, and no thoughts or worries for such things. However the Removal of Free Will is Evil, as now it exists, and is known, and experienced. To try and Remove it is an Act of Evil, and can be deemed so since Free Will exists. It can also be deemed not so, but this too is because of Free Will. Regardless of the Argument, The Presence of Evil does not disprove the existence of a God. Why does Evil exist? So that you may have Free Will, the ability to choice your path, and that it be your own, with its own impact, cascading across the paths of others in unpredictable ways.
This is my thought on the subject, and i hope i shed some light on the matter. if not, then feel free to comment otherwise, it is, of course, a matter of your own Free Will.
