I was not taking it as a biblical question, either, and it is in word evolution, not religion section of the forum. My thought was more along the lines of the quote “ the pen is mightier than the sword”, or something like that. A better definition of the topic in the OP would have helped out a lot, in this case. As far as the word “no”, most of the time, it doesn’t seem to mean much to people anymore, they just do what they want to do.
I had to go back to the OP after reading through the responses. It's a simple statement asking if you agree or disagree with it. Okay, I get it. It could be any word. To go on... Another question more specific asking more or less, do you agree or disagree that the word 'no' has no power? I get that too. In the English language every word has power even to the smallest degree. So I disagree with the statement. To the question of whether 'no' has power. It does.
Words have incredible power to shape the way we think about the world. For example, how can we communicate perceptions of tyranny to others if we don't have the word 'tyranny' or other words to describe it? For a more prosaic example, what we used to call the town or county dump is now the 'recycling center'. It affects the way you think about. One sounds a lot cleaner than the other.
Yes, words have power imo. The energy and power with the ability to help, to heal, to hurt, to harm, to humiliate and to humble, all through words or a word. How about the word 'love' powerful meaningful word, with a wide range of meanings and ability.