Even if you believe Christ was just a man, you have to admit human rights began with his humble birth
Even if you view Jesus Christ simply as a human being, not the Word Incarnate, on Christmas Day we still celebrate one of the most epochal events in world history; his birth. However you look it at, the birth of this man was the start of an immense, culture-changing series of events that have resonated through history, and in almost all parts of the world down to the present day.
That it should have been the birth of a man in very humble circumstances, to a humble family in an obscure part of the Roman Empire that started this sequence of events only makes it more remarkable.
It is more remarkable still when we consider that he was executed by the Romans. Even if you take the Dan Brown view that Jesus disappeared off to the South of France with Mary Magdalene where he died a natural death in old age, it is still remarkable this his life led to the founding of such a world-shaping religion.