New Defender's Study Bible Notes
3:25 propitiation. The term “propitiation” (Greek hilasterion) originally referred to a pagan sacrifice to appease some angry god. In its Christian use, however, it represents a perfect sacrifice which would satisfy both the justice of a holy God who must punish sin and the love of a gracious God who would redeem sinners. The shed blood of Jesus Christ provides both.
3:26 just, and the justifier. The mystery of how God can be both “just” (or “righteous”) and “justifier” (or “ascriber of righteousness” to the unrighteous) can be solved only in Christ. It is “His righteousness,” not ours, by which we are “justified” (that is, “declared righteous”) by God, through receiving Christ by faith.