Freire is mostly concerned with colonialism, but more positively what he describes is a method for initiating and sustaining any movement--another subject I've been reading a lot about lately. One might argue (several have, in fact) that Christianity began less as an institution and more as a movement; one might further argue that it would be revitalized by rediscovering this movement orientation. In any case, as a movement Christianity necessarily shares language with other movements; in at least one case, other movements share language with Christianity--the language of "witness."
I hear the word witness and think of how a person conducts herself, and how others interpret that conduct as essential Christianity. That's not how Freire intends it; he's talking about the witness of Che Guevara and his ilk. But the picture he paints of witness as an idea-informing-action--witness as praxis--is a lot more dynamic, more inspiring, by his portrayal:
The essential elements of witness which do not vary historically include: consistency between words and actions; boldness which urges the witnesses to confront existence as a permanent risk; radicalization . . . leading both the witnesses and the ones receiving that witness to increasing action; courage to love (which, far from being accommodation to an unjust world, is rather the transformation of that world in behalf of the increasing liberation of humankind); and faith in the people, since it is to them that witness is made.
All authentic (that is, critical) witness involves the daring to run risks, including the possibility that the leaders [those giving witness] will not always win the immediate adherence of the people.
A good reminder that witness--that of the Christian or that of the anarchist--is a gift offered for the benefit of the other, not a commodity to be hoarded as precious. We may die for our witness; we might trust that our death would then bear fruit.