Conflicting messages

From today's first reading, Isaiah 26:4:

Trust in the LORD forever!
For the LORD is an eternal rock.

That image of God has been with me for years--God as the bedrock, the rock that lies beneath the earth, below our feet, entirely solid and unshakeable.  It's an image that helps me get through hard times and reminds me of the solidity of my own call to be God's own.

I just read another image of Advent--one that contradicts the image of bedrock, or, rather, makes that rock an earthquake.  It comes from Alfred Delp, SJ, who died a martyr, executed by the Nazis in 1945 for his resistance.

In a sermon for the first week of Advent, Delp describes the "shaking" that the Advent lectionary discusses, shaking that anticipates the coming of the Lord at the end of time.  He says we need to be shaken, to feel instability, so that we know "inner movement and restlessness of heart" that bring us to God and to clear knowledge of our world.  

Delp says, "That is the first Advent message: before the end, the world will be set quaking.  And only where we do not cling inwardly to false security will our eyes be capable of seeing the Ultimate."  

We need to be awakened our of our sleepiness, to be aware of God in our lives and our desire for God, and to know of our final destination in God, which cannot be shaken.