Is God (θεός) Himself an Atheist?
(Since this definition is based on the Western concept of monotheism, we might expand it to include the Hindu religion or one who denies the existence of any gods.)
What is clear from the growth of the theological tradition in the Biblical text is that the early God of the Hebrews was one of many Semitic gods found in the pantheon usually located atop a high mountain peaks such as the Biblical Sinai or Horeb and it is within this polytheistic society that the first Commandment of Exodus 20 was written.
[An Excursion: The Evolution of “God” in the LXX: A Note on Genesis 1:1
In the early epic cycles in the Hebrew Bible, not only in J and E in in Genesis and Exodus, but as redacted in the Tribal League epics in the Deuteronomistic History of the Tetratuch, the concept of the deity of the Hebrews / Israelites moves from a local god who is but one member of a pantheon of gods which create the world (הארץ) for his people which he rules over to a latter universal single monotheistic deity of the LXX drawn from the Classical Greek concept of θεός.
Genesis 1: 1

This plural form of god is emended in the Old Greek and carried in to the LXX as:
εν αρχη εποιησεν ο θεος τον ουρανον και την γην
(Note: אלהים the plural masculine of אל or singular for god (see: Marvin Pope excellent comments in his classical study: El in the Ugaritic Text, EJ Brill 1955; pp. 1 - 21 and for a more up to date study see: John Day, Yahweh and the Gods and Goddesses of Canaan (Sheffield Academic Press, 2000)
Genesis 1: 1 clearly states that the world of the Hebrews was formed by a polytheistic assembly of gods just as one would expect in the Semitic cuneiform text of the ancient Near East such as the Enuma Elish.
How in the hell does אלהיםwith יהוהequal κύριος ὁ θεός? I would emphatically state that during Israel’s evolution from polytheism to monotheism has totally eclipsed the Semitic etymology here in favor of the non-Semitic Greek. ]
Since Yahweh demands the Hebrews / Israelites put him first over all the other gods (Please note: Nowhere does Yahweh say these other gods don’t exist, but rather that only he alone wants to be their god-king). Thus, it is plainly obvious that Yahweh himself believes in other gods just a these other gods also believed in him or (to put it another way; Yahweh is not an atheist). Thus, under Josiah’s reforms, all other Beth El’s or other Houses of Gods must be destroyed thus cutting off their food and leaving only Israel’s leading god’s (Yahweh) temple in Jerusalem alone honored with sacrifices.
In conclusion, when we come to the LXX and the New Testament (which is based on the LXX) we do not find Yahweh as simply another god fearing other deities of the Israelites anymore (or even the name Yahweh itself), but an alone and the only real Theos who himself no longer believes in any other living deities, but considers all other forms of competing gods simply worthless and dead idols (See the atheistic theologies to wards other gods in the Acts of the Apostles and St. Paul’s theology). Put another way, the Theos of the New Testament is now fully an atheist when it comes to belief in any god or gods!
Here a some closing questions to consider:
A. When did Yahweh lose his faith / belief in other Gods?
B. Why does the atheistic Theos (θεός) feel that the religious belief of the Semitic Yahweh was wrong?
C. Does the atheistic Greek Theos even deny the ancient Semitic, but religious
(faithfully believing) Yahweh himself?
D. Can the Biblical text reconcile the atheistic Theos with Yahweh’s faith in other gods? (Can the LXX and its later sibling (the New Testament) ever be really reconciled with the MT text? As I have already pointed out, to say that אלהים יהוה equals κύριος ὁ θεός is simply etymologically apologetic crap!)