All three religions -- Judaism, Christianity, and Islam -- hold that that the Old Testament is a holy book and the "word of god".
Members of all three relgions (not excluding your own, Christianity) frequently violate the code of ethics which is presented by the god of the Old Testament.
To say to a Jew or to a Muslim: your god is merely an "idol", not only denies the god of the Old Testament (which is also the god of the Christians, Jesus notwithstanding) but is also an extremely offensive and bigoted statement to make.
Yahalome, my dear, Christians do not have the exclusive ear of god, despite what the head of the Southern Baptist Convention, Bailey Smith, stated in 1987: "God almighty doesn’t hear the prayer of a Jew." (Y'all haven't come too far in 16 years, have ya?)
Of course, I personally believe that you ALL (Muslims, Jews, Christians, whatever) are silly buggers with your religious superstitions, religious prejudices, and religious rivalries.
But the silliest -- the most *contemptible* -- ones of all are the ones who claim that god listens to them, alone.