This is an interesting site.
The Origins of the Trinity DoctrineExcerpt: The Akkadians, too, grouped certain deities into trinities, like Anu, Bel, and Ea (the gods of heaven, earth, and waters), and Shamash, Sin, and Ishtar (sun-god, moon-god, and goddess of fertility). Tablet VI of The Creation Epic describes the building of Marduk’s temple (Esagila) in Babylon. In the following verse Marduk is given three names, “Anu-Enlil-Ea”: “For Anu-Enlil-Ea they founded his house and dwelling.” The gods of the Trinity of Thebes were the protector-gods of Thebes. In an Egyptian fresco Ramesses III is depicted with the Theban Trinity.
An Egyptian text of the 14th century BCE reads, “All gods are three: Amon, Re, and Ptah, and there is no second to them.” These three gods were subsumed into one of the three, Amon: “Hidden is his name as Amon, he is Re in face, and his body is Ptah.” This trinity is portrayed on a trumpet of Tutankhamen. An invocation in the Demotic Chronicle reads: “Apis, Apis, Apis! That is Ptah, Pre, Horsiese ... Apis is Ptah, Apis is Pre, Apis is Horsiese.” It formulates the unity of the three gods (Ptah, Pre, Horsiese) into one god, the god Apis. On an Egyptian amulet dating from the period around 100 CE, now in the British Museum, appear the three Egyptian deities Bait, Hathor, and Akori. On the opposite side of the amulet appears a distich (a strophic unit of two lines) which reads: “ One is {the god} Bait, one is {the god} Hathor, one is {the god} Akori - to these belongs one power. Be greeted, father of the world, be greeted, God in three forms {Gr. trimorjoV qeoV}.”
Excerpt: Here is something else that contributed to the confusing Jesus with God. God commanded, “You will not make wrongful use of the name of the LORD your God, for the LORD will not acquit anyone who misuses his name.” (Exodus 20:7 NRSV