To suggest, as the authors of "A Common Word" do, that Muslims and Christians are united by the same two commandments which are most essential to their respective faith and practice - love of God and love of the neighbor - is theologically dubious and politically dangerous.The scary thing is, if I were to ask you whether you thought modern, Western society more closely resembled a relational society or a centralised, controlling one, I think you'd agree we're closer to the latter. Perhaps we really are at risk of losing our Christian roots after all?
Theologically, this glosses over elementary differences between the Christian God and the Muslim God. The Christian God is a relational and incarnate God. Moreover, the New Testament and early Christian writings speak of God as a single Godhead with three equally divine persons - Father, Son and Holy Spirit.
This is not merely a doctrinal point, but one that has significant political and social implications. The equality of the three divine persons is the basis for equality among mankind - each and everyone is created in the image and likeness of the triune God.
As a result, Christianity calls for a radically egalitarian society beyond any divisions of race or class. The promise of universal equality and justice that is encapsulated in this conception of God thus provides Christians with a way to question and transform not only the norms of the prevailing political order but also the (frequently perverted) social practices of the Church.
By contrast, the Muslim God is disembodied and absolutely one: there is no god but God, He has no associate. This God is revealed exclusively to Muhammed, the messenger (or prophet), via the archangel Gabriel. As such, the Koran is the literal word of God and the final divine revelation first announced to the Hebrews and later to the Christians.
Again, this account of God has important consequences for politics and social relations. Islam does not simply posit absolute divisions between those who submit to its central creed and those who deny it; it also contains divine injunctions against apostates and unbelievers (though protecting the Jewish and Christian faithful).
Moreover, Islam's radical monotheism tends to fuse the religious and the political sphere: It privileges absolute unitary authority over intermediary institutions and also puts a premium on territorial conquest and control, under the direct rule of God.