It is rather silly to translate a Greek word into an English word or phrase, that then has to be explained using yet a third set of English words or phrases. Translating the Greek noun "hilastērion" (G2435) into "expiation" or "propitiation" or "mercy seat" or "sacrifice of atonement" are terrible translations. BGAD says the word means "means of expiation" but then the meaning of "expiation" must be explained. Again, according to BGAD, the idea is the "removal of the impediments to a relationship with God's self." Or in other words, Christ provides, through faith, the means of reconciliation. So why not leap-frog all these intermediate steps, and cut to the chase?
So lets look at Romans 3:25, as translated by the NASB, and then using an interpretative translation that attempts to cut to the chase.
Romans 3:25a NASB
whom God displayed publicly as a [fn]propitiation [fn]in His blood through faith.
_____________
Footnotes:
propitiation = a means of reconciliation between God and mankind by paying the penalty for sin.
in = Or by
The "whom" refers to Jesus being set forth.
Displayed publicly refers Jesus being set forth both on the cross and in His gospel.
In His blood refers to our faith in Christ's sacrifice of His life on the cross providing the means of reconciliation
Propitiation refers to the place (Christ) where the means of reconciliation is set forth.
Interpretive Translation
God set forth Christ's sacrifice of His life as providing the means of reconciliation accessible through faith in His name.
So lets look at Romans 3:25, as translated by the NASB, and then using an interpretative translation that attempts to cut to the chase.
Romans 3:25a NASB
whom God displayed publicly as a [fn]propitiation [fn]in His blood through faith.
_____________
Footnotes:
propitiation = a means of reconciliation between God and mankind by paying the penalty for sin.
in = Or by
The "whom" refers to Jesus being set forth.
Displayed publicly refers Jesus being set forth both on the cross and in His gospel.
In His blood refers to our faith in Christ's sacrifice of His life on the cross providing the means of reconciliation
Propitiation refers to the place (Christ) where the means of reconciliation is set forth.
Interpretive Translation
God set forth Christ's sacrifice of His life as providing the means of reconciliation accessible through faith in His name.