God forgives (cancels the debt of) sin only by faith because Jesus paid the debt.
If God forgave the debt there is nothing left to pay, you either pay the debt off or the person owed can forgive the debt, it is either or and not both.
The faith is needed to humbly accept the forgiveness as pure undeserved charity.
God applies that forgiveness by faith, to all those who believe in and trust on the person and atoning sacrifice (blood, Romans 3:25) of Jesus Christ for the remission of their sin and right standing with God's justice; i.e., "not guilty," declared righteous.
You are making God’s forgiveness contingent, when God, as the absolute best Lover, is forgiving everyone, but not everyone is humbly accepting that forgiveness as pure undeserved charity, so the transaction is not completed for everyone. Matt. 18:21-35.
Jesus went to the cross to pay the sin debt, which payment is applied to those who believe in and trust on him and his atoning work.
God forgave the debt that could not be paid. You might read Lev. 5 to see how scripture defines the sacrifice.
Is it me. . .or NT apostolic teaching: "atonement through faith in his blood." (Romans 3:25)
Which will not save you from God's condemnation on your sin.
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 holding back the child of God from the Father, that child that is within every one of us.
Paul explain the difference:
Ro. 3:25 God presented Christ as a sacrifice of atonement, through the shedding of his blood—to be received by faith. He did this to demonstrate his righteousness, because in his forbearance he had left the sins committed beforehand unpunished—
This is not saying sins prior to Christ crucifixion sins were “unforgiven”, since they were forgiven, but the forgiven sinner was not “punished” (disciplined) prior to the cross for his sins.
In Ro.3:25 Paul presents a bold huge contrast between the way sins are handled today (after the cross) and the way repentant forgiven sins where handled prior to the cross:
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 in Greek the same 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, this I can experience today, while those prior to the cross could only experience an outward cleansing with animal blood.
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.
As Paul said: “We can be crucified with Christ”, which is not saying Christ was crucified instead of us and the only way we can be crucified with Christ is to have Christ crucified.
It was not possible for those prior to the cross to empathically experience being crucified with Christ.
Again, If sins prior to the cross are handled the same way as after the cross than there is no contrast as Paul presents it and they would both have been equally punished.
We are in a growing process, so God judges the hearts of people to determine who is saved and lost at the time they are taken.