I think you're missing something. It's not just important, it's crucial. Yes, Jesus' death is important, but without the Resurrection what would we have? You see, this is where I think this idea that Christians go to Heaven is damaging. You hear Christians talking about going to Heaven all the time, but not talking about the Resurrection much. What would we have without the Resurrection?
13 But if there be no resurrection of the dead, then is Christ not risen:
14 And if Christ be not risen, then is our preaching vain, and your faith is also vain.
15 Yea, and we are found false witnesses of God; because we have testified of God that he raised up Christ: whom he raised not up, if so be that the dead rise not.
16 For if the dead rise not, then is not Christ raised:
17 And if Christ be not raised, your faith is vain; ye are yet in your sins.
18 Then they also which are fallen asleep in Christ are perished.
19 If in this life only we have hope in Christ, we are of all men most miserable.
20 But now is Christ risen from the dead, and become the firstfruits of them that slept. (1 Cor. 15:13-20 KJV)
Paul said, "if in this life only we have hope in Christ, we are of all men most miserable". He also said that if Christ isn't risen we'd still be in sin.
I'd say that makes the Resurrection absolutely essential. That leads me back to my original question, "what was finished"? If we'd still be in sin and essentially hopeless, what did Jesus mean when He said, "it is finished"?