Quote from : Star Wars: Episode VI - Return of the Jedi Movie

The Emperor: Come, boy, see for yourself. From here, you will witness the final destruction of the Alliance and the end of your insignificant rebellion.
[Luke's eyes go to his lightsabre]
The Emperor: You want this, don't you? The hate is swelling in you now. Take your Jedi weapon. Use it. I am unarmed. Strike me down with it. Give in to your anger. With each passing moment you make yourself more my servant.
Luke: No.
The Emperor: It is unavoidable. It is your destiny. You, like your father, are now mine.