Christ Jesus died on the cross for the sins of the whole world.  That's the central core of all genuine Christian faith. 

Without the cross there is no Christian faith, because if Jesus did not die for us then we are still in our sins.  The cross of Christ is every bit as important to spiritual life and forgiveness of sin as the fact of Jesus' resurrection.

As Paul wrote to the early Christians, "... we preach Christ crucified..."  (1 Corinthians 1:23)  And again, in the very next chapter of the same book, the Apostle Paul says, "For I determined not to know any thing among you, save Jesus Christ, and him crucified."  (1 Cor. 2:2)

While we know, as followers of the Living Lord Jesus, that Christ is no longer on the cross (in other words, Christ is not dead, but alive forever), it is good to remember His death often until He returns for His own.  May that glorious day come soon, Lord Jesus!