If I had the power of persuasion, I would use it to convince people that drugs are bad. If I could convince them of that the world would be a better place. I would also use my power to convince everyone to eat veggies and fruits 3 times a day!
Of course I would use it for good and I would use it to persuade people to do stuff I believed in, but not bad stuff, stuff like; persuading them that drugs are bad, not breakig the law, all the bad stuff people do, I would persuade not to do them.
The power of persuasion is when you convince someone to do something or to buy something or to believe in something or to do whatever you want.