"Until now the spirits of truth and falsehood struggle in the hearts of men and they walk in both wisdom and folly. According to his portion of truth, so does a man hate falsehood, and according to his inheritance in the realm of falsehood, so is he wicked and so hates truth. For God has established the two spirits in equal measure until the determined end, and until the Renewal, and He knows the reward of their deeds from all eternity. He has allotted them to the children of men that they may know good [and evil, and] that the destiny of all living people may be according to the spirit within them at the time of the Visitation."It's actually taken awhile for me to get onboard with this. But I am there now. It's really the only explanation which makes sense.
Dead Sea scrolls. Community rule (On the two spirits in man)