The other day I wrote about "rankism," the abuse of rank to insult the dignity of others. In talking to Bob Fuller, who coined the term, it struck me that combating rankism requires more than just raising the consciousness of individuals that "that's not nice." To use rank without abusing it requires new social movement to create new social types.
Christian thought is full of movements and social types of those who respect those of lower rank. The notion that all souls are equal before God is the root of democracy. The servant-leader follows the model of Christ to lead by serving, even unto death. The great saints cheerfully serve "the least of these." Somewhat more secular version of Christian ethics, such as chivalry and the Lady Bountiful -- indeed, the whole idea of gentility as a way of ennobling the warrior code -- are fruits of the "dignitarian" impulse (to use another of Fuller's terms) in Christianity.
Nietzsche thought Christianity was itself the triumph of slave morality. I think it is rather a triumph of a dignitarian morality among the powerful. Christianity encourages the self-humbling of those of high rank.