I think a more essential question to ask is why ANY sin was ever forgiven under ANY circumstance!
Trying to do the right thing and failing.
Doing the wrong thing on purpose.
Failing to do the right thing by doing nothing.
Thinking the wrong thing.
Being born unable to do the right thing.
Learning "right" and "wrong" and being taught incorrectly.
Among all the above conditions of "sin" the only obvious one is Doing the wrong thing on purpose.
But, consider this.
A person's life consists of Birth..........in between...............Death.
SIN takes place in that "in between" period. What happens when there is TIME REMAINING for a person to REPENT?
Christianity gives a sort of half-baked mechanism for forgiveness.
However, not consistent within Christianity is agreement on how it is possible in the first place.
Primarily, forgiveness consists of Jesus' Death and the sinner's belief in that death as a pre-condition for absolution.
Then, things are mucked up by the introduction of a Doctrine called GRACE.
Several versions of GRACE have appeared and have been taught historically.
1.Sanctifying GRACE (we are, by nature, partially divine already). St. Thomas says that "grace is nothing other than a certain participated likeness of the divine nature."(7)
2.Sovereign GRACE (Calvinist) Divine "arm-twisting" forcing worthless sinners to repent and accept God's love against their own nature.
3.Irresistable GRACE God foreordains who will be saved and it cannot be otherwise. In effect Holy Spirit, "graciously causes the elect sinner to cooperate, to believe, to repent, to come freely and willingly to Christ."
4. Prevenient GRACE (Augustine/Arminian/Methodist) Essentially, God turns a spiritual valve and allows us to experience our "natural" love and spiritual longing to operate that we may accept Christ's offer.
5. Means of GRACE (Luthern) God "plants" faith in human hearts and does not depend on the faith, strength, status, or good works.
And so on...
Bottom line conclusion?
The idea of what sin really is or how man escapes justice for what he actually chooses to do is distorted, convoluted and fragmented in theology.
If you break it you buy it is on the one hand fully enforced by JUSTICE and in another instance a FREE PASS is extended by God's whim.
So: it is NONSENSE.