The law of action states that in order for our desires to manifest we must take action towards manifesting our desires into our physical reality. Your actions must match your thoughts and when your actions and thoughts are aligned then manifestation takes place.
Action is required towards making our goals and dreams come true. Our desires will not manifest without us playing our part. The Universe acts in accordance with the actions we take. When we take a step the universe does the same. If we stand still and do nothing, the Universe stands still too.