“Whom God hath set forth to be a propitiation through faith in his blood, to declare his righteousness for the remission of sins that are past, through the forbearance of God;”
King James Version (KJV)
3:25 Whom God hath set forth - Before angels and men. A propitiation - To appease an offended God. But if, as some teach, God never was offended, there was no need of this propitiation. And, if so, Christ died in vain. To declare his righteousness - To demonstrate not only his clemency, but his justice; even that vindictive justice whose essential character and principal office is, to punish sin. By the remission of past sins - All the sins antecedent to their believing.
Ro 3:25 Whom God hath set forth [to be] a propitiation. Christ was publicly shown forth as a MERCY SEAT (a Propitiatory). As God of old met Israel at the mercy seat when the blood of the atonement was offered (Ex 30:6), so Christ on the Cross is our mercy seat. There we meet God who comes to us then in tender mercy, to declare his righteousness, to show it to us, in bestowing righteousness upon us in forgiving out past sins. This system of forgiveness, or righteousness through the cross of Christ, is the righteousness without law predicted by the Law and the Prophets.