Pastor and author J.D. Greear writes:

I remember a Muslim asking me when I lived in Southeast Asia, why would God need somebody to die in order to forgive our sin? He said, "If you sinned against me, and I wanted to forgive you, I wouldn't make you kill your dog before I forgave you. Why would God require some kind of sacrifice to forgive?"

Here's how I answered him:

Choosing to forgive somebody means that you are agreeing to absorb the cost of the injustice of what they've done. Imagine you stole my car and you wrecked it, and you don't have insurance and or the money to pay for it. What are my choices? I could make you pay. I could haul you before a judge and request a court-mandated payment plan. If you were foolish enough to steal my $1.5 million Ferrari (No, I do not actually own a Ferrari), you might never pay it off, and you'd always be in my debt.

But I have another choice. I could forgive you …. What am I choosing to do if I say, “I forgive you”? I'm choosing to absorb the cost of your wrong. I'll have to pay the price of having the car fixed. ... You have no debt to pay—not because there was nothing to pay, but because I paid it all. Not only that, I'm choosing to absorb the pain of your treatment of me. ... I'm choosing to give you friendship and acceptance even though you deserve the opposite.

This is always how forgiveness works. It comes at a cost. If you forgive someone, you bear the cost rather than insisting that the wrongdoer does. And that is what Jesus, the Mighty God, was doing when he came to earth and lived as a man and died a criminal's death on a wooden cross.