Impermanence is the load-bearing claim: the other two marks follow from it. If nothing persists, then nothing can be held without loss (dukkha), and there is no unchanging core to be a self (anatta). The tradition means it at every scale — geological, biographical, and momentary, down to the doctrine that mind-states arise and vanish faster than they can be counted. What makes it religious rather than merely true is the instruction attached: not "therefore despair" but "therefore stop clutching." Meditation practice is largely the business of watching arising and passing until the nervous system believes what the mind already concedes.