“He then began to teach them that the Son of Man must suffer many things and be rejected by the elders, chief priests and teachers of the law, and that he must be killed and after three days rise again.” (Mark 8:31)
Why was it necessary for Jesus to suffer in order for our sins to be forgiven? Tim Keller describes it best:
“When someone really wrongs you, a debt is established that has to be paid by someone. It can happen at an economic level. What if a friend of yours accidentally smashes a lamp in your apartment? One of two things can happen as a result. Either you can make him pay — “That will be $100, please” — or you can say, “I forgive you, that’s okay.” But in the latter case what happens to that $100? You have to pay it yourself, or you have to lose $100 worth of light and get used to a darker room. Either your friend pays the cost for what was done or you absorb the cost. This works at levels beyond the economic, too. When someone robs you of an opportunity, robs you of happiness, of reputation, or takes way something else that you’ll never get back, that creates a sense of debt. Justice has been violated — this person owes you. Once you sense that debt, again there are only two things you can do.
One thing you can do is to try to make that person pay: You can try to destroy their opportunities or ruin their reputation; you can hope they suffer, or you can actually see to it. But there’s a big problem with that. As you’re making them pay off the debt, as you’re making them suffer because of what they did to you, you’re becoming like them. You’re becoming harder, colder; you’re becoming like the perpetrator. Evil wins. What else can you do? The alternative is to forgive. But there’s nothing easy about real forgiveness. When you wan to harbor vengeful thoughts, when you want so much to carry out vengeful actions but you refuse them in an effort to forgive, it hurts. When you refrain, when you forgive, it’s agony. Why? Instead of making the other person suffer, you’re absorbing the cost yourself. You aren’t trying to get your reputation back by tearing their reputation down. You are forgiving them and it is costing you. That’s what forgiveness is. True forgiveness always entails suffering.
So the debt of wrong doesn’t vanish: Either they pay or you pay. But here’s the irony. Only if you pay that price of forgiveness, only if you absorb the debt, is there any chance of righting the wrong. If you confront somebody with what they’ve done wrong while you’ve got vengeance in your heart, they probably won’t listen to you. They’ll sense that you are not seeking justice but revenge, and they’ll reject anything you say. You’ll just perpetuate the cycle of retaliation, retaliation, retaliation. Only if you have refrained from vengeance and paid the cost of forgiveness will you have any hope of getting them to listen to you, of seeing their own error. And even if they don not listen to you at first, your forgiveness breaks the cycle of further reprisals. If we know that forgiveness always entails suffering for the forgiver and that the only hope of rectifying and righting wrongs comes by paying the cost of suffering, then it should not surprise us when God says, “The only way I can forgive the sins of the human race is to suffer — either you will have to pay the penalty for sin or I will.” Sin always entails a penalty. Guilt can’t be dealt with unless someone pays.
The only way God can pardon us and not judge us is to go to the cross and absorb it into himself. “I must suffer,” Jesus said.
-From King’s Cross by Tim Keller (p. 100-101)