Evil is not a tool, it is a state. Ignorance is often the root of evil acts, but the most evil acts are those done without ignorance. Full knowledge of action and reaction damns the traitor.
By saying, I know not, is one dissolved of the transgression? No, this is the purpose of formal forgiveness. To give someone a nother chance to excel. A fore-gift, a giving of something to someone ahead of the chance to earn it.
Evil is the state of anything done that is done primarily or solely for the individual who performs it or orders it done, without regard to the consequences put upon him or herself, the people that surround them, or the environment in which they live. The actions of a man who steals food for his family is less evil than the actions of a man who steals a boat for another man. The man who brings his family into addiction or strife is more evil than the man who abandons his family. The man who prays on the street solely for the recognition as a 'holy man' is in an evil state.
Evil is not solely power, pursuit, or potential, for even absent of these things, evil can be present. The man who abandons his life seeks no power, has no aspirations, and cuts himself off from himself, and yet he does it solely for himself, to end his perceptual misery.
Evil and Good are not Right and Wrong. You can do all the right things, for all the wrong reasons. The man who saves someone's life, not to share in their relationship but to make the man make good on a debt, that saviour is in a state of evil. There are mistakes, and then there is evil. Knowingly doing something destructive or reckless, even when you have safer, more civil, or simpler alternatives is the litmus.
Evil is not truth, it is knowing the truth and acting with the worst possible intent.