What alphabet does the common abbreviation Xmas for Christmas originate?

Xmas is a common abbreviation of the Word Christmas.

The "-mas" part is from the Latin-derived Old English Word for Mass,

while the "X" comes from the Greek letter Chi, which is the first letter of the Greek Word Χριστός, translated as "Christ".

There is a common misconception that the Word Xmas stems from a secular attempt to remove the religious tradition from Christmas by taking the "Christ" out of "Christmas".