Christ Jesus died on the cross for the sins of the whole world.  That's the central core of all genuine Christian faith.  The actual suffering and death of Jesus was far worse than most symbolic pictures ever show.  When you look at the picture above, you can barely recognize the image of a human being.  This helps to convey the actual truth.

The Bible says that Jesus was mutilated beyond recognition.  There was more to His suffering than the crucifixion itself, since He was tormented and beaten all night and most of the morning leading up to the cross.  For more information, see the Old Testament prophet of Isaiah, in chapter 53 of his book (in the Holy Bible).

The day when Jesus died on the cross was a dark day for all the world.  And yet we Christians call it "Good Friday" in our remembrance and celebration (yes, celebration) of the day.  Of course, we are really working up to celebrating His resurrection (traditionally on Easter Sunday).  But the day that Jesus hung on the cross until death is truly a great and necessary day for human beings everywhere. 

In Christ Jesus, God Himself was reconciling the lost human race to Himself.  This is not just some religious act on the part of sinners.  The crucifixion of Christ is God's own act of love and sacrifice for the whole world.  Because Jesus was willing to die on the cross for our sins, we can be now saved from the eternal consequences of our sins.  Jesus paid the price for all our rebellion and disobedience.  Now anyone anywhere can believe and be forgive of sin.