Romans 5:5 → Isaiah 28:16

Paul's assurance that "hope does not disappoint us" (Romans 5:5, hē elpis ou kataischynei) uses the same verb — kataischynō, "to put to shame" — that carries the LXX form of Isaiah 28:16, "the one who believes will not be put to shame" (ou mē kataischynthē). The echo precedes by five chapters Paul's explicit double citation of Isaiah 28:16 at Rom 9:33 and 10:11, signaling that the Isaianic faith-promise is already shaping his vocabulary of vindication. The logic is identical: the believer's hope is grounded not in self but in the divinely-laid foundation (the love of God poured out through the Spirit, secured by Christ's death, vv. 5-8), and that hope therefore cannot end in eschatological disgrace. This is the precise function of the Isa 28:16 LXX form Paul will later deploy as an OT proof of justification by faith. The method is Promise-Fulfillment by echo: the Isaianic promise that faith is never shamed is realized in the believer whose hope rests on the cornerstone Yahweh laid. The telos is the unshakable confidence of trusting Christ — the security Isaiah promised is now experienced as poured-out love, so that "not put to shame" is not a bare verdict but the joyful certainty of the one whose hope is fixed on a foundation that holds.