Here is something to think about to help you address the questions below:
The cross is foolishness to the nonbeliever, so it takes a lot to show the logic and benefit.
The Crucifixion is described allegorically by Christ, Paul, Peter, John (in Revelations) and the Hebrew writer as a ransom payment.
Paul in Ro. 3:25 giving the extreme contrast between the way sins where handle prior to the cross and after the cross, so if they were actually handle the same way “by the cross” there would be no contrast, just a time factor, but Paul said (forgiven) sins prior to the cross where left “unpunished”, but that also means the forgiven “sinner” after the cross were punished.
From Romans 3: 25 Paul tells us: God presented Christ as a sacrifice of atonement, through the shedding of his blood—to be received by faith. …
Another way of saying this would be “God offers the ransom payment (Christ Crucified and the blood that flowed from Him) to those that have the faith to receive that ransom.
God is not the undeserving kidnapper nor is satan, but the unbeliever is himself is holding back the child of God from the Father, that child that is within every one of us.
Paul goes on to explain:
Ro. 3: 25 …He did this to demonstrate his righteousness, because in his forbearance he had left the sins committed beforehand unpunished
I do not like the word “unpunished” since the same Greek word also means “undisciplined”.
So prior to the cross repentant forgiven people (saved individuals) could not be fairly and justly disciplined for the rebellious disobedience, but after the cross if we repent (come to our senses and turn to God) we can be fairly and justly disciplined and yet survive.
God and Christ would have personally preferred Christ’s blood to remain flowing through his veins, but it is I that need to have that blood outside of Christ flowing over me and in me cleansing my heart. I need to feel that blood and know it is cleansing me.
If you think about the crucifixion, you would realize at the time, Christ was on the cross God in heaven out of empathy/Love for Christ would be experience an even greater pain than Christ. We as our Love grows and our realization of what we personally caused Christ to go through will feel the death blow to our hearts (Acts 2:37). We will experience the greatest pain we could experience and still live, which is the way God is disciplining us today and for all the right reasons because Loving discipline correctly accepted results in a wondrous relationship with our parent.
Here are some questions I used in my adult Bible class:
Roman 3 starting with Ro. 3:24
1. Prior to Christ going to the cross where some people forgiven of their sins and if so who, how and why?
2. (God “pass over sins” or as in the NIV “left the sins committed beforehand unpunished”) so which sins in the past are these?
3. The OT gives lots of severe punishments for sins, so could/did “severe sins” go unpunished? Did God allow/want them to go unpunished? Why have these severe rules and punishments in the law?
4. Where the forgiven sins of those before the cross forgiven the exact same way as those after the cross?
5. If some sins where forgiven before the cross, was the cross needed to forgive sins?
6. From your own experience how hard was/is it for you to forgive the transgressions of your truly repentant child? Was/is there other action you have/had to see to that was harder to do? (What are/was it?)
7. Did you punish or discipline your children? (What would Dr. Dobson say?)
8. From your own experience with your children, if your child correctly accepted your most wise discipline and purely charitable forgiveness; was your relationship with your child better after or before the disobedience?
9. Is disciplining your child a learning maturing growing experience?
10. How could your rebellious/disobedient child stand “justified’ and “righteous” before you even today?
11. Look at the example Christ gives with the prodigal son (Luke 15: 11-32). Who is the kidnapper, what ransom was paid, who was set free, and could the son stand “justified” and/or “righteous” before the father?
12. Rev. 5: 9 “…and with your blood you purchased for God, persons from every tribe and language and people and nation.” Who did Christ pay?
13. What reason would Christ have for paying satan?
14. If God forgives our sins why would they still have to be paid for?
15. If Christ paid for our sins, why do they still need to be forgiven?
16. Atonement (propitiation) sacrifice can be for everyone with the ransom payment being offered but the kidnapper may refuse to accept the sacrifice, so it was made in vain for that kidnapper and the child is not freed?
35. RSV Ro 3:24 they are justified by his grace as a gift, through the redemption which is in Christ Jesus, NIV Ro 3:24 and all are justified freely by his grace through the redemption that came by Christ Jesus. How can we be “justified” like we kept the Law without keeping the Law?
What is the relationship between being justified and being righteous?
36. “Redemption” is an interesting word, so what does it mean here?
37. If we are being paid for and set free: who is hoping us captive, what are we being held from, what is the ransom being paid, who is being paid the ransom (who is the kidnapper), what value/benefit would this ransom have to the kidnapper, and how does “faith” play into this?
38. Verse 25 might help explain “redemption”, but v.25 is not easy to understand, so what does this verse mean?
39. If Paul is conveying the idea of a “ransom” which the context might suggest than it would be in keeping with other times Paul, Peter, Christ, John and the Hebrew writers use the analogy of a ransom in describing atonement or what happened with the crucifixion, so who is being paid off?
40. “sacrifice of atonement”, “atonement cover on the ark of the covenant”, “expiation”, “mercy seat”, “propitiation” and “propitiatory sacrifice”, all refer to what God put forward with Christ, so what was God doing?
41. What are we specifically putting our “faith” in to have this atonement take place or does it take place without involving our faith and some of us just do not receive it?
42. If we do not receive it does it take place for us? Is that similar to God’s Love, forgiveness and mercy?
43. Why are we even involved?
44. Is this to help make God righteous or to show the righteousness God already has?
45. This one little phrase of Paul: “because in his divine forbearance he had passed over former sins” becomes a thorn in the flesh for most theories of atonement. So what does it mean?
46. What does it mean for God to “pass over sins” or as in the NIV “left the sins committed beforehand unpunished”? Does it mean accumulate them? Roll the sins forward? Forgiving the sins without doing something else that is needed and maybe can be accomplished with the cross?
47. Is God passing over and/or leaving the sins unpunished, mean all sins or just some sins and which ones did He pass over (leave unpunished)?
48. If you go back to the OT and see all the “punishments” there were for sins, does that look like God is passing over them?
49. There is a contrast in V.25 between what we have after the cross and what there was before the cross, so did Christ going to the cross solve the problem moving forward and/or did Christ crucifixion undo God’s passing over sin in the past?
50. If Christ by going to the cross eliminates God’s need to pass over sins than why did God ever pass over sins since “time” is not a factor (Christ went to the cross from the beginning of time), so what effect would Christ have on past sins God passed over?
51. V. 26 How is God shown as being right (fair/just) with Christ going to the cross? Is it fair/just to allow the innocent to be tortured, humiliated and murdered, and the guilty to go free?
52. V. 26 In what way do we become justified while those that were previously pasted over could not be justified?