Paul's predication of the term $hilasterion$ of Jesus combined with his mention of Jesus' own blood leads modern interpreters to speculate that $hilasterion$ was a term that could denote a sacrificial victim-hence: "whom God put forward as a $sacrifice\; of\; atonement$ by his blood" (Rom 3:25, NRSV). But this is unsupported by the Greek sources. This dissertation examines all the known occurrences of $hilasterion$ outside biblical and Byzantine Christian sources, of which there are about eight-half of them new to this study. All can be glossed by "(sc. $anathema)\; propitiatory\; gift\; or\; offering$" (LSJ). Since $hilasterion$ never designates a sacrificial victim, the NRSV lacks support. Its meaning would rather be expressed by $hon\; prosenengken$ (not: proetheto) $ho\; theos\; hilasterion\; thusian$ (cf. P. Fay. 337). The tendency to parallel Rom 3:25 and 4 Mace 17:22 (codex S) is also misguided. Obviously the phrase $to\; hilasterion\; tou\; thanatou\; autwn$ (referring to the martyrs) cannot mean "the victim of their death." The background is rather to be sought in the normal Greek practice of offering durable propitiatory gifts (not victims) to the deity-hence: "their death as a $propitiatory\; votive\; offering$." Paul's use of $hilasterion$ is rooted not in the Greek but in the biblical world. Here $hilasterion$ refers most famously to the "mercy seat," the golden plate with the cherubim above Israel's ark of the covenant. Philo saw the mercy seat as "a symbol of the gracious power of God" (Mos. 2.96; cf. Fug. 100). Paul applies this symbolism to Jesus because it makes him the centre not only of $atonement$ for sin (Leviticus 16) but of the $revelation$ of God (Exod 25:22; Lev 16:2; Num 7:89). The terms $dikaiow$ and $apolutrwsis$ in Rom 3:24 pick up the language of the exodus (esp. Exod 15: 13) and enable Paul to present Jesus as the centre of the ideal sanctuary (cf. Exod 15: 17).