Explaining The “Sins That Are Past” of Romans 3:25
“[Jesus Christ] 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 [self-restraint or tolerance] of God;” (Romans 3:25).
Does the Bible teach here that we are only forgiven of our past sins? What are these “sins that are past?” In this Bible study, we will tackle this most troubling phrase.
Some believe and teach that, once we trust Jesus Christ as our personal Saviour, God will forgive us of our sins only up to that point in life. These are said to be the “sins that are past” in Romans 3:25. Whatever sins we commit after we trust Christ, we are urged to confess them daily (“short accounts with God”). First John 1:9 is then ripped out of its context here: “If we confess our sins, he is faithful and just to forgive us our sins, and to cleanse us from all unrighteousness.”
Whenever we encounter an obscure or difficult verse, we would do well to look for another verse to provide further light. Hebrews 9:14-15 is the best cross-reference to Romans 3:25:
“ How much more shall the blood of Christ, who through the eternal Spirit offered himself without spot to God, purge your conscience from dead works to serve the living God?  And for this cause he [Jesus Christ] is the mediator of the new testament, that by means of [His] death, for the redemption of the transgressions that were under the first testament, they which are called might receive the promise of eternal inheritance.”
Here above, we see how God dealt with Israel’s sins committed under the Old Covenant. Paul’s revelation not only gives us new information (the mystery gospel, and program), it also further explains the prophetic program (concerning Israel - what God has been revealing since man’s creation).
The nation Israel was commanded to offer animal sacrifices, but this animals’ blood did not take away sins. “For it is not possible that the blood of bulls and of goats should take away sins” (Hebrews 10:4). Those animal sacrifices typified, or previewed, the perfect blood of Jesus Christ that would one day be shed on Calvary (this blood would be efficacious in taking away sins—see Hebrews 10:1-22 in its entirety).
The Nation Israel will receive national forgiveness at Christ’s Second Coming (Acts 3:19-21; Romans 11:26,27; Hebrews 8:8-13; Hebrews 10:15-17).
What national Israel has yet to experience, we (of “the body of Christ”) have now received in Christ (Romans 5:11; cf. Romans 3:21-31). God was fair in passing over Israel’s “time past” sins because Christ’s blood, His propitiatory sacrifice, would permanently cover them. Despite their historical idolatry, Israel will still be His people one day by virtue of the New Covenant!
The traditional interpretation of “sins that are past” really makes no sense; that is how we know it (this statement in Rom. 3:25) does not apply to our sins. If God forgives us today of all our past sins, those we committed prior to coming to faith in Christ, then that means that He can and will impute sin to our account.
If there is so much as one sin on our account when we die, that would mean we go to Hell! It would be a contradiction of Romans 4:8, which says that God will never again reckon sin to our account as members of the Church, “the Body of Christ”: “Blessed is the man to whom the Lord will not impute sin” (Rom. 4:5-8). Christ’s righteousness has been applied to our account, and that will never be rescinded. God cannot hold us accountable for sin if He already held Jesus Christ responsible. Colossians 2:13 says God has forgiven us Christians of “all trespasses.”
13 And you, being dead in your sins and the uncircumcision of your flesh, hath he quickened together with him, having [already] forgiven you all trespasses; Colossians 2:13 (KJV)
Thus, the phrase “sins that are past” (Romans 3:25) could not refer to our past sins. It refers to Israel’s past sins committed under the Old Covenant (Mosaic Law). The blood of Christ will be the basis of the New Covenant, which will take care of Israel’s Old Covenant sin debt.
by Shawn Brasseaux https://forwhatsaiththescriptures.org/2018/04/06/sins-that-are-past/