primarily "a phantom or likeness" (from eidos, "an appearance," lit., "that which is seen"), or "an idea, fancy," denotes in the NT (a) "an idol," an image to represent a false god, Acts 7:41; 1 Corinthians 12:2; Revelation 9:20; (b) "the false god" worshipped in an image, Acts 15:20; Romans 2:22; 1 Corinthians 8:4,7; 10:19; 2 Corinthians 6:16; 1 Thessalonians 1:9; 1 John 5:21 .
"The corresponding Heb. word denotes 'vanity,' Jeremiah 14:22; 18:15; 'thing of nought,' Leviticus 19:4 , marg., cp. Ephesians 4:17 . Hence what represented a deity to the Gentiles, was to Paul a 'vain thing,' Acts 14:15; 'nothing in the world,' 1 Corinthians 8:4; 10:19 . Jeremiah calls the idol a 'scarecrow' ('pillar in a garden,' Jeremiah 10:5 , marg.), and Isaiah, Isaiah 44:9-20 , etc., and Habakkuk, Habakkuk 2:18,19 and the Psalmist, Psalm 115:4-8 , etc., are all equally scathing. It is important to notice, however, that in each case the people of God are addressed. When he speaks to idolaters, Paul, knowing that no man is won by ridicule, adopts a different line, Acts 14:15-18; 17:16,21-31 ."* [* From Notes on Thessalonians, pp. 44,45 by Hogg and Vine.]