The Disjointed and Unity Concepts of G-d

The Christian belief in G-d does not deny the concept of a G-d, but it allows for another divine autonomy to co-exist. Judaism, on the other hand, insists upon G-d's unity, rejecting any other perspective. This is the reason a Jew must not enter a church. On the other hand, under Jewish law, a Gentile is under no obligation to adhere strictly to monotheism, as long as he accepts G-d.

The Islamic view of G-d coincides with the Jewish view, which is why no prohibition exists for a Jew to enter a mosque. The fact that Muslims pervert the idea of G-d, in Whose name they'll commit the most heinous crimes, is a separate issue. That has to do with their role model, their "prophet", who Maimonides calls "The Idiot" (המשוגע). For a grown man to "marry" a 6-year-old girl, the word "idiot" is a compliment.

Since any name you'd give G-d seems inapropriate, in terms of defining the undefinable, the Jewish language uses the word "Oibershter", which means The Above. This way, no matter what concept one has, use of that name implies, "It's above that too." In Hebrew, G-d is often called "The Name" (Hashem).  Here too the title implies remoteness, something like "whatever-you-call-it".

The 2nd principle of Maimonides' 13 principles of Jewish faith addresses this "Unity of God". But the word "unity" requires qualification: It means to say this is the quintessential idea of Oneness. It is not like the oneness of a pair (as in, a pair of doves - one group) and not "one", as of a species, as, e.g., a man, that has many members in this group. Nor like a body, with many components. Rather, G-d is one and there is no other oneness like His.  A Jew meditates on this fundamental every day when he recites, “Understand (Listen) Israel, Hashem Our God, Hashem is One!”