What God requires of us he himself works in us, or it is not done. He that commands faith, holiness, and love, creates them by the power of his grace going along with his word, that he may have all the praise.
History teaches us these lessons for the interveners: leave your prejudices at home, keep your ambitions low, have enough resources to do the job, do not lose the golden hour, make security your first priority, involve the neighbours.