While Satan's power is limited by God, it is great indeed. One day he'll give that power to an emerging leader on the world's stage who the Bible refers to as the Antichrist. He'll deceive many that he has their best interest at heart, but his heart is to be worshipped and to control everyone's entire life around the globe. Even today false teachers exist for the same desire, and will use whatever demonic tactics they can to trick you. So make sure that if someone's teaching goes against the Bible, stop listening and start running!