"Everyone asks for firmness in faith, but few firmness in love.  They ask for faith and are ashamed of love, such arrogant hearts; faith has no idea of the place where love transports you."  So said seventeenth century Sufi Muslim Bahu.  What does he mean? 
Perhaps he is suggesting that however much we believe in God (or, for Bahu, Allah (the Arabic word for God) in this life, we really do not have any idea of the glory that awaits us in the hereafter.  We cannot, on planet earth, comprehend God's fullness, we cannot, in the here and now, grasp fully the ultimate richness of God's love for us.  Though we believe it, we cannot see it; and while we live and die by it, we will not experience its completion until we leave this world.
     As Paul notes in his first letter to the Corinthian church, "Things which eye has not seen and ear has not heard, and which have not entered the heart of humankind, all that God has prepared for those who love him" (1 Corinthians 2:9).
     How can we measure such things?
     This, I think, is Bahu's point.  In this life, we cannot.  All we can do is trust, in faith, in God's love, to believe in its certainty, to hold to its permanency, to hold to its ultimacy.  
     And how do we know this love?  In this second week of Advent (to jump from Islam to Christianity!), we have our answer:  Jesus Christ.  Because Jesus was born in history, died in history, and rose again in space and time, we have reason to yes, be firm in faith, but even more to pursue the firmness of love.
     As Paul notes later on in the same letter, "But now faith, hope, love, abide these three, but the greatest of these is love."