All things can happen, but there is always a price.
The price is attached to existing, not only to choosing. To exist is to do — especially for a being with free will — and to do is to pay. Most payment is ordinary: the energy it took to do the thing.
Generosity does not break the law. Someone still pays; it is just not the one who receives.
Absolution is a form of payment, not a cancellation. It can take many forms. Forgiveness is one of them, when the chance is given, taken in good faith, and backed up with action.
The price law is universal. Sin is not: what counts as sin is cultural and subjective.