Everything above is what the traditions confess. Historians of ancient Israelite religion describe something different, and the two accounts should be kept apart rather than blended. The critical account is not a claim about whether God exists. It is a reconstruction of how the texts and the worship came to look as they do, built from a small and contested epigraphic record.
The name YHWH first appears outside the Bible on the Mesha Stele, the Moabite inscription of about 840 BCE, which speaks of carrying off "the vessels of YHWH". Earlier Egyptian topographical lists at Soleb and Amarah West name a Shasu land of yhw in the fourteenth century BCE, which many scholars connect to the divine name and to a southern, Midianite or Edomite, origin for the god. That connection is argued, not established. Several archaic biblical poems place YHWH's approach from the south: Seir and Edom in Judges 5, Teman and Mount Paran in Habakkuk 3.
El is the other thread. El heads the Canaanite pantheon in the Ugaritic tablets and is also the ordinary Semitic word for a god, and the Hebrew Bible applies El's own titles to the God of Israel: El Elyon, El Shaddai, El Olam, El Elohei Yisrael. Mark S. Smith's account, standard in the field, describes a process of convergence, El's characteristics, and later some of Baal's, drawn into YHWH, followed by differentiation, the deliberate exclusion of everything else. Deuteronomy 32:8-9 is the pivot text: the Masoretic Text has Elyon apportioning the nations "according to the number of the sons of Israel", while the Septuagint and a Qumran copy read "sons of God", giving a scene in which the Most High divides the nations among divine beings and YHWH receives Jacob as his share. Psalm 82 has God standing in the divine council and passing sentence on the other gods.
Inscriptions found at Kuntillet Ajrud in the northern Sinai, dating to about 800 BCE, bless by "YHWH of Samaria and his asherah" and "YHWH of Teman and his asherah", evidence, on most readings, that popular Israelite religion in that period was not what the biblical writers wanted it to be. What asherah denotes there, a goddess or a cult object, is itself disputed.
The usual reconstruction therefore runs from monolatry, the worship of one god without denying that others exist, to explicit monotheism, the denial that any other exists at all. The clearest statements of the second are exilic: Isaiah 45:5-7, "I am the LORD, and there is no other; besides me there is no god." Julius Wellhausen's nineteenth-century source criticism supplied the framework, much of its detail has since been revised, and the developmental picture has held.
None of this is what Judaism, Christianity or Islam teach about themselves, and it is here because an atlas that reports only confessional accounts is not reporting. A reader who holds the traditional account should read this section as the historian's reconstruction it is; a reader who holds the critical account should note that it is a reconstruction, and that several of its load-bearing pieces, the Shasu identification, the sense of asherah, the date of the shift, are contested by specialists.