“The charming aspect of Christmas is the fact that it expresses good will in a cheerful, happy, benevolent, non-sacrificial way. One says: “Merry Christmas”—not “Weep and Repent.” And the good will is expressed in a material, earthly form—by giving presents to one’s friends, or by sending them cards in token of remembrance….”
http://en.wikipedia.org/wiki/Sol_Invictus#Sol_Invictus_and_Christianity_and_Judaism
http://en.wikipedia.org/wiki/Saturnalia