1 Corinthians 8:4

Concerning therefore the eating of things sacrificed to idols, we know that no idol is anything in the world, and that there is no God but one.

'we know' -with absolute confidence and certainty. Yes, absolute truth does exist!

'no idol is anything in the world' -Idols or images did exist and at times in great number (Acts 17:16). Paul is saying that every idol was simply the image of. non-existent god, and hence an image representing nothing.

And this truth still holds true! If all the "gods" of Egypt, Babylon, Assyria, Greece and Rome..were false, then so are all the "gods" of India, Africa, the South Pacific and North America.

'there is no God but one'. Deuteronomy 6:4; Ephesians 4:4.

'The two propositions together form. strong affirmation of monotheism over against every form of polytheism (worship of many gods) or henotheism (the acceptance of many gods). Not only is there only one God, but there is. correlative denial that idols have any reality at all.' (Fee p. 370)

'one' -note: 'One' doesn't always mean 'one person or one individual'. If "two" can be found in. "one" (1 Corinthians 6:16); then three (Father, Son, Holy Spirit) can also be included in. "one". (John 10:30 'I and the Father are one'), that's at least two persons who are included in the designation of 'God'.