It's somewhat Pollyannish to say, "Christianity is just about the Resurrection, and not the Cross." To say that is to deny the gritty evil in the world. But once you get past childhood and start reading serious books and watching more sophisticated films, you find people desperately wrestling with evil. That's what any serious novel, film, or play is about. Just look at any of Shakespeare's plays--there's always someone engaging profound evil. Therefore, it doesn't make sense to say, "Let's not focus on the Cross; it's too sad, too dark, too evil."
Pressing the issue theologically, what is the Cross? It's God journey into God-forsakenness. God enters into human dysfunction in all of its forms. In the Passion narratives you have cruelty, violence, hatred, injustice, stupidity--all of human dysfunction is on display. And Jesus enters into that, thereby redeeming it.
The Church fathers liked to say, "What has not been assumed has not been saved." Jesus assumes the human condition in all of its dysfunction, going all the way down, so to say. And it's only for that reason he can bring us all the way up.
The Resurrection without the Cross is superficial, just as the Cross without the Resurrection is despair. It's the play between the two that matters.