Worship the same God
Both Judaism and Islam are staunchly monotheistic, believing in the existence of one — and only one — God. Many Americans understand that Jews and Christians worship the same God; however, they may be unaware that Muslims also worship that very same God.
Allah is not the personal name of some altogether separate and distinctly different deity (like Odin or Thor, or Zeus or Apollo, or Vishnu or Shiva); the term Allah does not specify some peculiar, foreign, alien, or uniquely Arabian god. Rather, Allah is merely — and quite literally — the Arabic word which means “God.” (Arab Christians, for example, refer quite naturally and unselfconsciously to their explicitly biblical God as “Allah,” since for them that unloaded term is nothing other than simply Arabic for “God.”). The Quran, Islam’s holy book, discusses Adam, Noah, Abraham, Moses, David, Solomon, Jesus, and other biblical figures; in doing so, the Islamic scripture itself makes it abundantly clear that the God of Muhammad, and the God of Jesus, and the God of Israel are all the selfsame God. Since the Muslim God is also the Judeo-Christian God, Allah is in fact identical with — and not different from — the Hebrew God of Abraham, Isaac, and Jacob.
Indeed, Judaism, Christianity, and Islam are together regarded as “Abrahamic” religions, insofar as all three of them share common roots, which are traditionally traced back to the ancient Hebrew patriarch Abraham. (As founded by Muhammad in the 7th century AD, Islam was born in Arabia, and both Jews and Arabs are likewise classed as “Semitic” peoples; each group is traditionally regarded as descended from Shem, a son of Noah.)