Our Desire for God 

When I have the experience of desiring "I know not what," I am experiencing God creating me now in all the particulars of my present existence.  While immersed in the experience I do not worry about my past failures and sins or about what the future will hold.  I feel at one with the universe and as whole as I could possibly be.  Moreover, the desire I experience is the deepest desire within me.  That desire is in tune with God's one intention in creating the universe, and that desire can become the ruling passion of my life, if I let it.  I believe that this desire comes from the Holy Spirit who dwells in our hearts.

When we experience the desire for "I know not what," it is God's Holy Spirit drawing us into the community which is the Trinity.

This deepest desire of our hearts is for God.  While we are in the throes of this desire, everything else we might desire takes a back seat, as it were.  Everything else becomes relative before the absolute Mystery we desire.  Moreover, insofar as this desire reigns in our hearts, we also desire to live out our lives in harmony with this desire.  Hence we want to live in harmony with God's creative purpose for us, to choose what will be more in tune with our desire for union with God.
 

Barry, S.J., William A. Finding God in All Things (Notre Dame, IN: Ave Maria Press, 1991) p.40-41.