This vain angel, wanting glory for himself, lied to Eve. Adam was not worthy to live forever in paradise. Adam lost perfect human life in paradise for himself, for his family, and for us. Satan's actions raised deep questions. Jehovah allowed time for the answers to become clear.
Happiness is elusive.
The rule of men causes suffering. A faithful remnant of Bible students still exists. Men have failed to find happiness. They have failed to govern themselves well. Satan has failed to cause all men to rebel.