Knowledge is something you acquire by experiences and by teachings. Using the knowledge you acquire during your lived life you will be confronting the adversities which will be appearing to you so you have the power to overthrew the adversities.

The person who is called wise is because it has a lot of knowledge. Is the middle ages, the kings were considered wise men although not every single king was it. The really wise kings usually had a lot of power and also succeed in their roll of king by choosing the correct way to overthrew the adversities.

Another example is in "Back to the future" the movie. A very intelligent man(a lot of knowledge) invented a time machine, he had the power of changing future facts and also the past facts which consequently change the future. I thing if you can change future facts or either past facts you can have a lot of power, as well as money which clearly shows that knowledge and success lead us to power.

To conclude , I think "knowledge is power" because knowledge , directly or indirectly , if your use it in the appropriate way, leads us to power as it did in the past, is doing now in the present and I hope it will do in the future,