My master (Dr. Tae Yun Kim) emphasized to me that blocking is really about the redirection or reflection of energy. If strong force is coming at you, you have several choices. You can step out of the way, or you can redirect the energy so that the blow misses you, or you can use their energy to throw them off balance, or you can reflect it back to them. Any of these can be very effective. It comes down to a keen understanding of these concepts, your own capabilities, the size and weight of your opponent, and of distance and timing.
Train hard, feel good, help others, and smile and be happy. :)