Since it’s close to #Christmas , I figured it was worth going through a quick history lesson on the origin of the abbreviation “Xmas”. Though well-intentioned, those who fight against the abbreviation b/c it “removes Christ from Christmas” are incorrect. 1/
In our Latin alphabet, we use the letter X/x (ex) in “Xmas”. It was originally the similar-looking Greek Χ/χ (χι) - which is the first letter in ΧΡΙCΤΟC (CHRISTOS, Christ). The abbreviation “Xmas” dates back at least to the 16th century, & other abbreviations predate that. 2/
Using abbreviations for “Christ” & other “sacred names” (“nomina sacra”) in the original Greek biblical manuscripts actually dates back to ancient times, possibly the original text itself. Here is an example from the Codex Sinaiticus (Acts 9:34) c. AD 325: 3/ 
This abbreviates [Ι]ΗCΟΥ[C] [Χ]ΡΙCΤΟ[C] (Jesus Christ) & places an overline to signify that the words are sacred. Many other words were also signified as “nomina sacra”, including ΦΕΟC (God), ΚΥΡΙΟC (Lord), ΥΙΟC (Son), & ΠΝΕΥΜΑ (Spirit). 4/
Even outside of New Testament text, it was common to abbreviate & overlined “nomina sacra” by the 1st & last letter, 1st 2 letters & last letter, or other shortened forms. 5/
But this dates even further back than just Christianity. In the Old Testament / Hebrew Bible, Jewish scribes used the tetragrammaton “יהוה” of God’s divine name (“YHWH” in English for Yahweh/Jehovah). 6/
Though it is not known specifically why the Greek (& other language) New Testament manuscripts used their specific nomina sacra notation, theories point toward the overline in ancient Greek numerals, combined w/ the phrase ”the 1st & the last” from Revelation. 7/
The TL;DR version: “Xmas” has a basis in very strong Christian tradition of sacred name abbreviation that possibly dates to the original Biblical texts themselves. 8/8
