Battle of good versus evil
The subtle battle of good versus evil has been waged periodically since the earliest times.
Everything in the Universe has originated from the One God. The God principle permeates everything in the Universe and also exists beyond it. From this perspective both good and evil have originated from the God principle. They have both existed since the creation of the Universe. However the evil was in seed or latent form at that time.
Since both good and evil come from the Supreme God principle, they also get their spiritual energy from God. This may seem like a paradox; however it can best be understood by the following analogy. Two employees of a company work equally hard and earn the same wage. After the money is in their hands, it depends on them how they will use it. One person may use it to feed himself and after that whatever is remaining to help society. The other person may use it to harm society. Earning money is akin to obtaining spiritual energy that we get when we do spiritual practice. The intention behind doing spiritual practice is very different for good and evil people. For the former, it is to merge with God whereas for the latter it is primarily to get spiritual power. Once we build up our reservoir of spiritual energy, God gives us the free will to use it as we please. This spiritual energy when used by people for Righteousness is known as good energy and when used for unrighteousness it is known as evil energy.
At every twist and turn, evil forces in the Universe are trying to adversely influence the balance of power. Despite the demonic forces’ constant attempts to reduce the subtle Sattva component and stop seekers of God from practising and spreading spirituality, the good forces reign supreme as long as there are Saints and seekers doing spiritual practice. This is because God helps Saints and seekers due to their Devotion, to overcome the evil forces.
The major reservoir of power of good and evil resides in the subtle regions. The forces of good and evil on Earth are like puppets on strings. They both get their power from the forces of good and evil respectively in the subtle realm.
Courtesy: Forum for Hindu Awakening