"Not to know Scripture is not to know Christ." These words of St. Jerome were not an exhortation to Christians of his own time to read the New Testament, but an encouragement to deepen their knowledge of the Old Testament, the Bible of Israel. What was true in the late fourth century is no less valid today. Much of the imagery and many of the biblical texts we associate with Christmas can only be understood in their full depth if we are aware of their Old Testament roots.