For many years as a Christian, I was not entirely sure what the significance of the resurrection was. I knew Jesus died on the cross for my sins, but what exactly was the deal with the resurrection? Somehow it was linked to hope, but I did not know how. Though it was not a focus of study for me, I found the answers I got from looking around and asking other Christians to be generally the same and generally lacking.
The most common answers I got ranged from Jesus rising from the dead to "beat death" to the resurrection being a sort of proof that Jesus' bloody "payment" was accepted by God: "the check has been cleared", so to speak. There are elements of truth to these answers, for there there are many facets to be found, but it was not until I read the work of the late Lutheran theologian Gerhard Forde that I began to really understand what the resurrection was for, and why it was necessary in conjunction with His death on the cross.
The short answer is that Jesus rose from the dead to bring in the new creation. He is the beginning of something new for us. His death was the end of the old... the old way, the old age that finds every one of us condemned and guilty of failing to live up to our humanity, the old system that corporately and individually finds itself comfortably at home in unbelief and defiance against God's good and sovereign care. And His resurrection was the birth of the new age, the new creation, which all who belong to Him will inherit with Him. He is the "first fruits" of this new creation. So in sum, what makes His resurrection so important? His resurrection means that there is a new beginning for mankind. The end is no longer the end. There is something new, a new and living hope which is as real and tangible and definite as His resurrected body.
So, now back to the cross. What I'm realizing is that one must go with the other. If our understanding of the cross leaves us with a weak or almost unnecessary resurrection, we are missing something essential. And likewise, if our understanding of the resurrection leaves us with a weak or almost unnecessary death on the cross, then we have drifted far from the truth. Thus, we have a question here. If Christ's resurrection meant the beginning of something new for us, the beginning of a new age and new creation which we can be a part of, then why did Jesus have to die? Or more importantly, why did Jesus have to die in the way that He did?
After all, it is obvious that one must first be dead in order to resurrected from the dead, but there are many ways the Messiah could have died. He could have died as an infant. He could have died in an accident. He could have died from a disease or from old age. Those are indeed all aspects of this fallen world which identify with all of humanity. So why a cross?
Considering that there are voluminous works on this subject from many great minds over the centuries, I'm not going to even attempt to claim that I have illuminated the answer to that question. But I do have some thoughts based on Scripture and what I have read.
The death of Christ on the cross assumes the curse for us by entering the place of the condemned man in our stead, ahead of us. That is true. It says as much: "cursed is the man who hangs on a tree." But there is more. It is by the death of the Messiah in this manner that the Jews of the time, in particular, and all men corporately are exposed for what they are. We are exposed for all of our indifference, faithlessness, spiritual pride, treachery, and wickedness. Jesus died as "weak" at the hands of the "strong," outcast and condemned as a criminal. There the irony stands in blinding brilliance: the innocent, righteous Son of God, the Savior of mankind who came bringing the Kingdom of God to earth, is hated and condemned and rejected, but it is his condemnation by our own hands that stands as the greatest and starkest condemnation of us all. For the Gift of God, the Savior of the World, to be betrayed and killed as a criminal in the world's eyes shows just how screwed up and self-deceived and lost and warped we really are. By the Son of Man allowing us to judge and condemn Him, He stood outside of the world's system as the ultimate indictment against it.
And yet it is by this very death and what followed that we are saved, purely as a gift, by no contribution of our own whatsoever. This dark and dismal indictment turned to news of joy and deliverance as breath entered His lungs early that Sunday morning.