(Before It's News)
1 ”Behold, I send my messenger to prepare the way before me, and the Lord whom you seek will suddenly come to his temple; the messenger of the covenant in whom you delight, behold, he is coming, says the LORD of hosts.
2 But who can endure the day of his coming, and who can stand when he appears? “For he is like a refiner’s fire and like fullers’ soap;
3 he will sit as a refiner and purifier of silver, and he will purify the sons of Levi and refine them like gold and silver, till they present right offerings to the LORD.
4 Then the offering of Judah and Jerusalem will be pleasing to the LORD as in the days of old and as in former years.
5 ”Behold, I will send you Eli’jah the prophet before the great and terrible day of the LORD comes.
6 And he will turn the hearts of fathers to their children and the hearts of children to their fathers, lest I come and smite the land with a curse.”

Source:
http://www.catholicnewsagency.com/calendarday.php?date=2016-12-23#rd_0