The assumption is that those who seek control are bad and those who empower others are good.
One might say that empowering a criminal might not be necessarily a good action, yet empowering in itself doesn't mean give someone more power which can be used to destroy, but to give power which can be used to create. So in short empowering means to me giving somebody power to create more, while control is to suppress somebodies creative powers or support only those creative powers which can be used to control others.
Here are examples of controls vs empowerment from above article.
A person who seeks to teach others how to garden and thereby grow their own food is practicing empowerment and is therefore GOOD. But a person who seeks to place other people on government food stamps and thereby make them dependent on government for their food is practicing control and is inherently EVIL.
A school that teaches students to think for themselves and engage in critical, skeptical thinking about the world around them is practicing empowerment and is therefore GOOD. But a school that teaches students blind obedience to institutional authority while denying them the liberty to think for themselves is practicing control and is therefore EVIL.
A person who seeks to help others create their own successful businesses and generate abundant profits for themselves and their employees is practicing empowerment and is therefore GOOD. But a person who seeks to destroy entrepreneurship, suppress innovation, punish small businesses and burden private sector job creation with onerous taxes and regulation is practicing control and is therefore EVIL.
A person who seeks to teach others how to protect themselves against violent crime through the intelligent, ethical use of weapons for self defense is practicing empowerment and is therefore GOOD. But a person who seeks to strip away from everyone else their right to self defense, placing them in the position of defenseless victimization, is practicing control and is therefore EVIL.
A city mayor who seeks to teach his constituents the principles of nutrition and food choice so that they might make better decisions about their diet and health is practicing empowerment and is therefore GOOD. But a city mayor who demands blind obedience to his selective agenda of banning large sodas or other junk food items is practicing control and is therefore EVIL. (Bloomberg, anyone?)
So, getting back to the title of this article, the way to instantly tell whether a person is "good" or "evil" is to examine their actions on the control vs. empowerment spectrum. If they predominantly seek to control others, they are mostly evil. If they predominantly seek to empower others, they are mostly good.
Be careful to examine peoples' actions, not merely their words. Anyone can talk a good game of "empowerment," but very few actually seek to educate and uplift others around them.