Anyone who has ever had children will know that it is a most Augustinian experience. Few if any parents of a three month old find Pelagius and his ilk to be particularly persuasive on the matter of human nature. Indeed, it is very hard not to believe in original sin at 3 am in the wee small hours when your child is screaming his lungs out and there is nothing - no food, no toy, no activity, no person - which can stop him. Babies are the most brutally honest of human beings: it really is all about them; and they make it very clear that they both believe that and practice such with a vengeance.
Infants are, in fact, the very embodiment of self-love. They want their immediate needs satisfied and they care nothing for anything or anybody else. Arguably, the process of growing up, of education in the broadest (and oldest) sense of the word, is the means by which the child comes to curb this utter self-centredness through its need to be part of wider society.
The irony of the Christian Christmas is that the Christ child comes not because of any need of his own or any desire to fulfill a selfish or inwardly directed want; this child, the child in the manger, considers it not robbery to be equal with God and yet humbles himself by taking the form of a servant in order to be obedient even to death on the cross. All of this is done for those who not only did not deserve it but who despise the very thought of grace. For the strong and the self-sufficient to be shown their need and to be delivered there from by a nobody who begins life in a manger and ends it on a cross is a profound insult to everything we hold dear. The world looks on - now as then - and see this all as so much childishness; the tragedy, of course, is that it is the unsuspecting world which is truly childish.
The message of Christmas is the message of the cross: all our human conceptions are turned upside down; greatness is found in a manger and on a cross; the most powerful autonomous aspirations of men and women are in comparison to the baby Jesus but childish acts of meaningless defiance; atheism pretends to maturity; but from the perspective of the Bethlehem stable, it is but so much juvenile posturing