Given the following passage  "Jehovah's Witnesses believe that the Bible condemns the mixing of religions, on the basis that there can only be one truth from God, and therefore reject interfaith and ecumenical movements. They believe that only their religion represents true Christianity, and that other religions fail to meet all the requirements set by God and will soon be destroyed. Jehovah's Witnesses are taught that it is vital to remain "separate from the world." The Witnesses' literature defines the "world" as "the mass of mankind apart from Jehovah's approved servants" and teach that it is morally contaminated and ruled by Satan. Witnesses are taught that association with "worldly" people presents a "danger" to their faith, and are instructed to minimize social contact with non-members to better maintain their own standards of morality.",  answer the following question. Note that the answer is present within the text.  Question: Jehovah's Witnesses are concerned about the ways of whom?
Satan