Of what value is it if you have windows but you do not have any light at all ? explain this metaphorically

Examine this as light that would come in and light that would go out. The transparency of windows, the ability to see through windows, is the purpose of windows in this statement, allowing something to go in and out. What is the light in you? Now with this part of the statement, it is then expressing the metaphor as a direction from inside of someone to the outside. So it some one has a window, the ability or platform to say things and have people listen, what is the value if the person only speaks of hate and violent things. What value is there to listening to someone who speaks of these things through their "window"?

Let's consider the windows as opportunities to positively influence other people. An excellent situation would be a teacher. The have the "window", the class time to use effectively and beneficially for the students who are in the class. But what if the teacher only wants to pass the time and get through the class, not really imparting any knowledge, or being to lazy or indifferent or not caring. A window - the classroom, but no passion nor energy or light.

This example I believe best illustrates what it means to have a window, but no light.