In this world, an infant is the closest we see to a pure heart: someone who has never been bitter, never schemed, never manipulated, never held a grudge, never laid a trap, never plotted payback. The innocence of childhood is something that we hope that each new child can maintain because that innocence has both beauty and power. In some measure we adore the innocence and the possibilities for good that come from it. We admire it because we desire it. Holding an infant re-awakens all that we hope for, all that we ever hoped for.
It re-awakens our knowledge of what God hopes for: Peace on earth, goodwill towards humanity. We hold onto a child because it re-awakens the best in us too.
It is easy to let the mockers win the day. We don't fully trust the good to last; since when did we have enough strength to withstand the mockers without becoming tarnished ourselves? But when we have a child in our arms, it is easier to say: I will enjoy this moment and its promise. And so God comes to us in a way that not only holds all the promise of what he can be, but renews the promise of what we can be.
"The weakness of God is stronger than man's strength."