I don't actually know who the author of God Rest Ye Merry, Gentlemen is. No one does, really. It's believed to have been written more than 500 years ago. That's old. So instead of featuring the for-real author of this song, here are a few fun facts about it.
This is the only song mentioned in Charles Dickens' A Christmas Carol. Because of its singularity, it is -- for all intents and purposes -- the Christmas carol of the title.
Speaking of titles, let's talk about the comma, shall we? It's not between Ye and Merry, where many grammar rookies place it. The comma goes between Merry and Gentlemen. I know, right? What the heck?
The heck is that words change meanings over the centuries. Rest may have meant "to keep" and merry meant "strong" or "mighty" (such as in Robin Hood's "merry" men). Keeping that in mind, the title is not about happy fellows being urged to rest, which is what we might think today. The title may, in fact, be seen as a reassurance that God will keep these men safe and strong through Christ because Christ has been born on Christmas Day. Savvy?
But more important than pondering the placement of a punctuation mark is pondering the meaning of the words. Think on this stanza (circa 1760) today and tomorrow as you celebrate Jesus's birthday:
God rest you merry, Gentlemen
Let nothing you dismay
For Jesus Christ our Saviour
Was born upon this Day
To save poor souls from Satan's power
Which long time had gone astray
Which brings tidings of comfort and joy.