The first half of life is about "surviving successfully," as Rohr puts it. The second half is about giving ourselves away. As Jesus said, "For those who want to save their life will lose it, and those who lose their life for my sake will save it. What does it profit them if they gain the whole world, but lose or forfeit themselves?" (Luke 9:24-25)
While Rohr's thesis is hardly new, it is particularly relevant for our time, which Rohr argues convincingly is preoccupied with a first half of life spirituality. He is at his best in describing our resistance to moving into a spirituality for the second half of life.
St. John of the Cross taught that God has to work in the soul in secret and in darkness, because if we fully knew what was happening, and what Mystery/transformation/God/ grace will eventually ask of us, we would either try to take charge or stop the whole process. No one oversees his or her own demise willingly, even when it is the false self that is dying.
God has to undo our illusions secretly, as it were, when we are not watching and not in perfect control, say the mystics. That is perhaps why the best word for God is actually Mystery. We move forward in ways that we do not even understand and through the quiet workings of time and grace. When we get there, we are never sure just how it happened, and God does not seem to care who gets the credit, as long as our growth continues. As St. Gregory of Nyssa already said in the fourth century, "Sin happens whenever we refuse to keep growing." - Rohr, pp. 50-51.
This certainly rings true to my own experience. We need to be secure enough in our identity to give ourselves away so that we can receive our identity from God. We have to empty the container we create so that God can fill it with something altogether better than anything we could come up with on our own. This is faith: giving our container to God and becoming willing to have him do with it whatever he will. It isn't that the container is necessarily bad, but rather that it is inadequate to the fullness of life that God wishes to share with us. So we have to die in order to live.
Or be killed: the fate of Jesus and the prophets in most times and places. People locked in a first half of life spirituality focused on security perceive second half spirituality as a threat. And they are right.
It seems that it is only through falling - through failure, disappointment, loss and suffering - that we are opened to the Mystery that holds us in life even when we are in death. As Rohr reminds us, even Jesus descended into hell before he ascended into heaven.
We must go down to go up. That is how we keep growing.