Sometimes we get stuck in ways of living that are destructive to ourselves and others.  Sin has a stickiness to it that can make it difficult to extricate ourselves from a bad habit that we've started.  Over time, our conscience can become so dulled that we're no longer sure that we're doing is even wrong, so we no longer see the need to be rescued.  

The only hope of deliverance from such a situation is the presence of God himself.  Isaiah prays for just this in 64:1, "Oh that you would rend the heavens and come down!"  Drawing hope from examples of how God has rescued his people in the past, he asks for deliverance once again, even though he acknowledges they surely deserve judgment.  

Because his people have wandered so far from God's ways that they are no longer capable of turning to him on their own, his merciful intervention is needed.  His presence is needed.

And God did finally come to rescue his people from exile in Babylon and bring them home.  And God did crack the sky and come to earth in Jesus to lovingly and finally deal with the sin in our lives and offer us a way home.  This is the hope we celebrate at Easter.