From Latin idolum “image (mental or physical), form;” from Greek eidolon "appearance, reflection of oneself in water or a mirror, also mental image, apparition, phantom;" eidolon also means “any material image, statue,” from eidos “form” from Latinized form of Greek -oeides, from eidos “form,” related to idein “to identify,” eidenai literally “to idein-tify, to recognize, mental perception.”
Certain religions emphasize that one should not worship "idols":
"You shall have no other gods before me. You shall not make for yourself a graven image [idol], or any likeness of anything that is in heaven above, or that is in the earth beneath, or that is in the water under the earth; you shall not bow down to them or serve them..." - Exodus 20:2-5
This is generally interpreted to refer only to material, literal "idols," such as statues. However, the root word idolum indicates a mental or physical form, especially as a reflection of oneself. Thus, the idols we truly worship are mental images of ourselves: our egos ("I"), defects, desires, memories, resentments, etc. All of those mental idols in their chaotic, conflicting mass constitute the subconsciousness, which in ancient Greek writing was called Eidolon, meaning an apparation that has our form (image) but is inherently illusory.
What is necessary is for our inner divinity to make a true image within us, a real eidolon, which is solar, divine. This is what is indicated in Genesis:
"And Elohim said, Let us make Adam in our image, after our likeness." - Genesis 1:26