Christians vs. Muslims"-"the cross vs. the crescent"-"Christianity vs. Islam." Too often in recent years these titles have been paired in connection with political conflicts, military confrontations, or socio-ethnic tensions. Ultimately this has created the impression that Islam and Christianity are fierce antagonists whose only object is to tear each other to pieces. More or less consciously, the media have become accomplices in this propaganda which has generated fear and mistrust, if not actual hatred between the two groups: The mounting tension could blind us to the ties we have in common and distort our sense of proportion in the present situation. The pages presented here make no claim to arbitrate secular conflicts or to propose miraculous solutions. They attempt rather to identify the modern and traditional roots of these tensions, with an eye to the shared religious patrimony of Islam and Christianity and our common destiny in the face of the challenges of the modern world. We are brothers, not enemies.