Yes, the tendency towards monotheism was going on everywhere in the Mediterranean world during that era. Multiple gods were simply combined into ever more powerful, Voltron-like deities, and eventually one, all powerful god emerged.
The Egyptians were the pioneers of this, with many composite gods throughout their history, as the Pharaohs attempted to combine deities worshipped in different parts of the country into a unified, state sponsered religion. Early versions included Amun-Ra and Isis-Hathor. The real action came with the ascension of Akhenaten as Pharaoh, and his introduction of the world's first Monotheist religion: that of the Aten, or Ra-Horus, the universal sun-god. All other Egyptian religions were suppressed during his reign. However, this proved too radical for the Egyptians, and when he died (or was overthrown, it is unclear) the Aten religion was suppressed, and polytheism resumed. The story isn't over though. When the Greeks and the Romans conquered Egypt, they seized upon the tradition of combining gods, and engaged in it themselves, not just in Egypt, but throughout their empires. So you start to see deities like Serapis (Osiris, Apis, and Hades), Baal-Jupiter, Isis-Aphrodite etc etc. The final composite deity to compete with Christianity was that of Sol Invictus, or the Unconqurable Sun, another solar deity, combining Apollo, Ra, Horus, and any number of other solar deities.
Judaism of course was also heavily influenced by the dualistic Zoroastrian faith, and can be seen as a composite of Canaanite religion and Zoroastrianism, with the tendency towards monotheism driven by ambitious kings wishing to cement their power in the same manner of the Pharoahs. When Christianity came along, it seemed perfectly natural to combine Judaism with the philosophy of Socrates, the holy family of Horus, some of the life stories of heroes such as Hercules and Adonis, and a death and resurrection story akin to that of Orpheus, Dionysus, and any number of minor mythical figures.
The more you look at them in context, the less remarkable Christianity and Judaism appear.