Why: a person freed from these three gates of darkness practices what is good for the self, and thus attains the supreme goal, naming freedom from these three specifically as what actually opens the door to genuine, sustained good conduct.

In life: a huge amount of good conduct becomes naturally more accessible once these three specific root causes, desire, anger, greed, are actually addressed, rather than needing to force good behavior against their ongoing pull.

Teaching: rather than trying to force good conduct through willpower alone while these three root causes remain active and unaddressed, prioritize addressing the root causes first, good conduct becomes considerably more accessible once that underlying work is actually done.