It is earned. Authority is earned. And nothing earns authority faster than through an act of love. Love is the opposite of power. You cannot both love people and use your power against them.
Love gives rather than takes away.
It supports rather than oppresses. It cares about people more than ideologies. It creates an environment of hospitality rather than hostility. This is why martyrs influence vast numbers of people. When a person loves others enough to die for them, the people heap authority and credibility upon that person - the sacrificial death becomes a rallying point for the masses.