The climax of a movie is great but it's not the end. And without the end you don't experience the full arch of the narrative. You don't have a sense of completion and you don't see the grand scheme.
The cross is the climax but it's not the end. By itself, without the resurrection you've only got part of a story*. So that's why we bother with the resurrection...
"In his great mercy he has given us new birth into a living hope through the resurrection of Jesus Christ from the dead"
1 Peter 1:3
The cross was the method... It was the operation. It was the means to an end. It's only when you see the outcome that you begin to appreciate the purpose. When you're Face to face with the facts of the risen Jesus... A flesh and blood person who is without sin, who has conquered death and who can enter the presence of God - and then you suddenly realise the purpose of it all. JESUS did not die to sort out the problem of sin... That was not the main goal. Instead we should say... Jesus sorted out the problem of sin so that the relationship between God and his creation might be restored permanently. It's a subtle but impactful change of focus that can really make a difference... Will you regularly focus on your sin and how it put Jesus on the cross. Or will you focus on your restored relationship, as you regularly encounter the risen Jesus? I have known many well meaning Christians who never seem to look past the cross, but in doing so they miss the big point... a restored relationship!
" into an inheritance that can never perish, spoil or fade. This inheritance is kept in heaven for you..."
1 Peter 1:4
It's a sloppy title for a second point, It sounds just like the first I know but bear with me. I mean, by perspective, that it enables you to see the future and the now, and see how they work together. Resurrection is supposed to happen in the future. Christianity (just like a good amount of the Jews in Jesus's day) upholds the belief in a day of resurrection. When the dead will be raised and all will stand before the Lord. The curious thing about Jesus's resurrection is not that it happened... but that it happened early... Out of time. Anachronistically.
Did you know that tartan kilts weren't around in William Wallace's day? So when you see Mel Gibson in Braveheart... his clothes are from the future! Same goes for the redcoats in the 'Pirates of the Caribbean' ... The British military didn't introduce their infamous redcoats until at least 50yrs after the first film is set. The resurrection of Jesus is, in some ways, a glimpse of the future. It is seeing something that we thought would happen later, happening now. This helps us in two obvious ways. Firstly it means we know it will happen later. The confidence that Peter displays in 1 Peter 3 can be ours too. Because Jesus rose again, we know there is an inheritance waiting for us. And secondly, a glimpse of the future happening now, tells us that the future can happen now! And that is the experience of the church through the ages. Every time someone is saved, healed, restored... Every time someone has their tears wiped away by Jesus acting through His Church, we are witnessing the resurrection power of the future, breaking into the 'right now'.
I recently went to a bird sanctuary and saw how dedicated some people are about 'birdwatching'. They spend a lot of money and a lot of time, so that they can sit and wait and watch and... just maybe... they might see something amazing. On the wall in the Bird Hide is a whiteboard with all the recent sightings of interesting birds. And these people happily watch and wait, and invest... because if they do... eventually they'll see something amazing.
The Resurrection works like that whiteboard... We can know for a fact that the resurrection power has been experienced... in this LIFE. In this History and Time. So we, like birdwatchers, wait expectantly to see when it might happen next. Knowing it has happened (the risen Jesus) and knowing it will definitely happen in the future (the risen us!)
*The resurrection is not the end of the story either. The ascension, pentecost, the history of the Church... the story is still unravelling as we breathe. But sermons cant last forever