During our Korean Bible reading session, in which we are reading Leviticus, a member asked why the sacrificial system was instituted. To our modern senses, killing an innocent animal seems almost barbaric. 
I gave two answers. 1) It foreshadows what Jesus would do for us. He is the lamb of God that takes away our sin. 2) It shows the seriousness of our sin. Only the blood (either ours or someone else’s) can wash away the stain of our sin. 
After life, I think most of the world will be shocked to find out the graveness of their sin. What they thought was no big deal – something they scoffed at as prudish – will torment them day and night without end. 
We live in the world, but we are not of the world. We do not see good and evil from the eyes of the world. We see it from the eyes of God. Our sin is not murder, rape, racism, or adultery. We sin is rejecting Jesus. 
Therefore, our only hope is Jesus. Not our politics. Not our ingenuity. Not our technological advancement. Not positive thinking. 
He is not only the One who saves. But He is also the One we are saved into.