Remember the former things of old: for I am God, and there is none else; [I am] God, and there is none like me; (ASV)
Contrary to this (and contrary to the belief of many Christian and Jewish apologists), the Hebrews formerly believed in the existence of many gods. See the Deuteronomy 32:8 article for more on this.
umm... the bible itself reveals that the jews worshiped many gods...
- Jeremiah 1:16
And I will declare my judgments against them, for all their evil in forsaking me. They have made offerings to other gods and worshiped the works of their own hands.
I don't see this as a contradiction..
these passages (everyone you've cited) are to remind them that he's the only one who proved himself
- Isaiah 41:23
Tell us what is to come hereafter,that we may know that you are gods; do good, or do harm,that we may be dismayed and terrified.
..in 1 kings 18 you have many israelites worshiping Baal, proving they worshiped many gods, but YHWH proves that his authority.
not a contradiction at all for him to say he's the only one and they know it. they just rejected him.
- 1 Samuel 8:7
And YHWH said to Samuel, "Obey the voice of the people in all that they say to you, for they have not rejected you, but they have rejected me from being king over them.
Jeremiah 15:6 You have rejected me, declares YHWH
and wanted to be like the nations
Ezekiel 20:32 "What is in your mind shall never happen—the thought, 'Let us be like the nations, like the tribes of the countries, and worship wood and stone.'
to not incur their guilt for breaking the covenant.
Jeremiah 11:10 They have turned back to the iniquities of their forefathers, who refused to hear my words. They have gone after other gods to serve them. The house of Israel and the house of Judah have broken my covenant that I made with their fathers.
you are just proving a point proved within the bible itself, the jews were faithless, hence they endured horrible evil throughout their existence, to become a "byword" and a "laughingstock" of the nations, although they are never completely destroyed.
Jeremiah 3:6 YHWH said to me in the days of King Josiah: "Have you seen what she did, that faithless one, Israel, how she went up on every high hill and under every green tree, and there played the whore?
Deuteronomy 28:37 And you shall become a horror, a proverb, and a byword among all the peoples where YHWH will lead you away.
- Isaiah 10:21
A remnant will return, the remnant of Jacob, to the mighty God.
so once again..
5For even if there are so-called gods whether in heaven or on earth, as indeed there are many gods and many lords,
6yet for us there is but one God
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