When the peasants of England sang God Rest Ye Merry, Gentlemen more than 500 years ago, they understood a vastly different meaning from what people in America think today when they hear it.
"God Rest Ye Merry, Gentlemen" was sung for hundreds of years before being published in the 1800s. Queen Victoria loved Christmas carols so during her time this song began to find favor in the Anglican Church. Soon the protestant English clergy of that era were even enthusiastically teaching "God Rest Ye Merry Gentlemen" to their congregations. Moving to both Europe and America, the carol became a favorite throughout the Christian world. It is still sung in much the same way as it was five hundred years ago.
The problem is that few of today’s singers fully understand the beginning of the carol. This is because language is dynamic and words change over time.
Today, when people say Merry Christmas, they mean “happy.” Five hundred years ago, when "God Rest Ye Merry, Gentlemen" was written, “merry” had a very different meaning.
You know of Robin Hood’s "Merry Men." Now, they may have been happy, but in the time of Robin Hood the word “merry” that described them meant “great or mighty.” Thus, in the middle ages a strong army was a merry army, a great singer was a merry singer, and a mighty ruler was a merry ruler.
So when the English carolers of the Victorian era sang, "merry gentlemen," they meant great or mighty men. Even when translated to "God rest you mighty gentlemen," the song still makes very little sense.
This is because another word that has a much different meaning in today’s world and a punctuation mark that has been lost. The word "rest" in "God Rest Ye Merry Gentlemen" simply meant “keep or make.” Yet to completely uncover the final key understanding the meaning, a comma needs to placed after the word “merry.”
Therefore, in Modern English, the first line would read "God make you mighty, gentlemen." Using this translation the old carol suddenly makes perfect sense, as does the most common saying of the holidays, "Merry Christmas."
You just have to know how to translate the words into Modern English and have a very Mighty Christmas!