I believe we operate at various levels of consciousness. One end of the spectrum is a basic survival consciousness directly linked to physical attributes, our body/vessel, the machine for navigation of the physical reality. At the end of the spectrum is pure spiritual connectivity to the universe (or God, for lack of terms). When we shed our vessel upon death, we return to the body of God. We are what God is. Free will would become unnecessary.
I also believe that interwoven between these levels of consciousness and the constant interaction with the vessel, we sometimes encounter anomalies which permanently alter our brain function (our CPU and telecomm center). They can be brought on by birth defect, injury, sickness, environmental issues, psychological damage, etc. Defective "wiring" or damage at the molecular level within our DNA can affect our maturation and eventually shape how our physical consciousness perceives the environment, interpreting, and acting out. In essence, I believe we as purely spiritual beings are not evil. If our machine is defective, especially when gradual degradation allows the most severe symptoms to go unchecked, the interpretive level of consciousness becomes skewed and acts inappropriately.
Did I really say that? 