One of the books I’m reading now is John Stackhouse’s Making the Best of It: Following Christ in the Real World. He quotes David Martin as saying,
“If I wanted to dramatize it I would point out that Mohammed was a warrior and a family man whereas Jesus was neither. Again notice that Islam sanctifies a holy city and is about territory whereas primitive Christianity is not. Indeed, for the early Christians Jerusalem was abandoned to desolation. The connection which underpins these differences is the link between the blood tie as realized in the family and land, possessions and violence. Christianity rejects the social logic embodied in genealogy, biological reproduction, and land, and attempts to set up spiritual and non-violent brotherhoods and sisterhoods outside that powerful nexus.”
Stackhouse recognizes that, as Martin says, this is a dramatized account. While Jesus clearly relativized family connections (in terms of biological kinship), the concern for biological family was edging its way back into Christianity fairly early. We can also see, unfortunately, that the history of Christians, once they got into power, made the faith look like something concerned with territory.
For me, the strength of this way of differentiating Christianity and Islam is that there is material internal to the Christian tradition, and in particular, material identified with Jesus himself, that allows us to critique and relativize the common human propensity to center on biological kinship, value the holding of territory, and using violence to make sure things turn out well. For you who are scholars of Islam: What resources are available within Islam to relativize these attitudes?