Resistance is hinderance that interrupts inner advancement and progression. Despite the vastness of the water the fish swims with little effort and resistance, always moving forward unless it finds a place to slow down but always moving and always looking out for a change of circumstances and possible danger without getting aggressive (for the majority of fish).
Resistance captures energy without the form, yet retains the structure and it becomes impermanence and resistance to impermanence. Perseverance is the push against a resistance as the energy of impermanence pushes up and through the shell of resistance. Once understood resistance can be used for gain. Immunity is impermanence of external forces, a protection from opinions, attacks, manipulation and other detrimental affects.