An die Roemer, part 4: 1:18-23

1:18-23: Knowledge of God
Ἀποκαλύπτεται γὰρ ὀργὴ θεοῦ ἀπ’ οὐρανοῦ ἐπὶ πᾶσαν ἀσέβειαν καὶ ἀδικίαν ἀνθρώπων τῶν τὴν ἀλήθειαν ἐν ἀδικίᾳ κατεχόντων, διότι τὸ γνωστὸν τοῦ θεοῦ φανερόν ἐστιν ἐν αὐτοῖς· ὁ θεὸς γὰρ αὐτοῖς ἐφανέρωσεν. τὰ γὰρ ἀόρατα* αὐτοῦ ἀπὸ κτίσεως κόσμου τοῖς ποιήμασιν νοούμενα* καθορᾶται, ἥ τε ἀΐδιος αὐτοῦ δύναμις καὶ θειότης, εἰς τὸ εἶναι αὐτοὺς ἀναπολογήτους, διότι γνόντες τὸν θεὸν οὐχ ὡς θεὸν ἐδόξασαν ἢ ηὐχαρίστησαν, ἀλλ’ ἐματαιώθησαν ἐν τοῖς διαλογισμοῖς αὐτῶν καὶ ἐσκοτίσθη ἡ ἀσύνετος αὐτῶν καρδία. φάσκοντες εἶναι σοφοὶ ἐμωράνθησαν, καὶ ἤλλαξαν τὴν δόξαν τοῦ ἀφθάρτου θεοῦ ἐν ὁμοιώματι εἰκόνος φθαρτοῦ ἀνθρώπου καὶ πετεινῶν καὶ τετραπόδων καὶ ἑρπετῶν.
Indeed, the wrath of God is uncovered from heaven upon all of the impiety and unrighteousness of those people who in unrighteousness 1:[are withholding] the truth, inasmuch as that which is clearly known of God is 2:[clearly known by] them; for God made it clear to them. For that which from the creation of the world is unseen of God -- both the eternal power and divinity of God -- while being understood is clearly seen in God's 3:[deeds], so that that they are without excuse, inasmuch as having known God they neither valued nor praised him as God, but rather they were thoughtless in their accounting and their witless hearts were 4:[darkened]. They became foolish while presuming to be wise, and 5:[traded/mistook] the glory of the incorruptible God for an image in the likeness of a corruptible human, avian, quadruped, or serpent.
1: κατεχόντων - holding, as in they have possession of it, is a necessary assumption of the word. What is implied is propriety of a selfish sort, of holding for oneself, of controlling, of withholding or keeping something back. There are analogies to covering, to either veiling the face or covering over the grave.
2: iterating the complex forward - it "is in them," which may or may not make sense; it "is clearly known in them" makes more sense while only reusing what has been just given in such a way as to align with the following verb, and then we may say "clearly knowm by them" by analogy to the plain dative uses of en+D. This also involves taking the complex "τὸ γνωστὸν τοῦ θεοῦ φανερόν" in two pieces: a masculine genitive, "of God," embedded in a neuter nominative, "the clearly known thing." Paul (or more likely his amanuensis with the Roman birth-order name) is using better Greek than usual!
3: ποίημα - a thing done or made, from ποιέω, to do or make. Which is strictly an English distinction! In Ecclesiastes, we translate this word about half "deeds" and about half "things made." (All of which are, of course, futile in the end.) Now, in this passage we have already a reference to the construction of the world, which clearly colors existing translations toward the revelation being in creation, "in the things made." And if you ask a modern what God has done, creation will be right up there at the top of the list. But if you ask a first-century Jew or a first-century Christian convert what God has done, is that the answer you'll get? Why should these attributes, which have been hidden since creation, be revealed in creation? Why should they not instead be revealed in the actions by which God's people very specifically know this one to be God? Ascribing creation to God is always posterior to the actions by which we have come to know God as God.
4: ἐσκοτίσθη - "darkened," but skotos implies night-darkness, blindness, uncertainty. Not coloring, but absence of lighting. The organs of thought were cast into darkness such that they could not see to operate properly.
5: ἤλλαξαν - not "changed," as the incorruptible God and his glory cannot be changed, but rather referring to a mental action on the part of the people involved. The question of whether we say traded/exchanged, as a more clearly primary agentic act, or mistook/confused, as more clearly consequent to the sinful state, is a matter of taste, also secondary to the bare fact of idolatry in the face of knoweldge of God.
Idolatry. Giving to something else the value (glory) and praise that belongs to God. In this case, almost stereotypically, we're talking about graven images. And the wrath of God is revealed upon this because they know better! These people for whom God has acted as God -- and Paul is being awfully generic -- know the truth about God, and cover it over with the images of subordinate things. And Paul's generality covers his audience -- the Judeans will recognize a tale of Judean history, and the converts will recognize their own histories with idols. All of them, as church, know that God has acted to save them in clear and profound ways. All of them have come in these ways to know the eternal power and divinity of God, and to praise and (value) glorify that one as God. This is the joy of a juridical parable -- the audience agrees with you right up to the punchline! "This idolatry truly is impious and unrighteous, when we all know who God is and what God has done!" It plays on their wisdom, and their gnosis, with language that is so clearly biased to deprecate "those people," inexcusably thoughtless and witless, foolish without realizing it. (Not like us.)