RomRo. RomansRomanos, chaptercapítulo Epistle to the RomansCarta de Pablo a los Romanos, chaptercapítulo 1

Because, even though they in actual fact knew G-d, they did not ascribe Him kavod (glory) as G-d or give hodayah (thanksgiving) to Him, but became filled with hevel (futility, vanity, emptiness, worthlessness) in their thinking, and their senseless levavot were darkened.