Vicious, evil acts are perpetrated by people. The usual motive behind those acts is greed.
If you want to banish evil from the world start educating people. Begin with yourself.
Stop believing fairy tales: there is no satan, there is no wicked witch of the west.
Those that attribute the evil in this world to satan allow evil to persist. They refuse to see the true perpetrators. They don't ask themselves the right questions - such as: who gains from this evil act?
Always follow the money to find out who gains from evil. You will not come across satan by doing so - you will come across politicians, bankers, oil companies and corporate magnates.