Many people get bent out of shape when they see ‘Xmas’ or ‘X-Mas.’ They think it’s a way of removing Jesus Christ from Christmas. “Every year you see the signs and the bumper stickers saying, ‘Put Christ back into Christmas’ as a response to this substitution of the letter X for the name of Christ.” Nothing could be further from the truth.
Part of the problem is that most people have little historical background information related to the subject and a general ignorance of classical languages
“Christ” is a Greek word for the Hebrew word “anointed one” or “Messiah,” as in Handel’s “Messiah.”
The Greek word for Christ is Χριστος. The Greek alphabet does not have the letters “c” or “h.” You will find a “k” (kappa) and an “h” sound that looks like a single opening quotation mark that looks like this: ‘. It’s called a “rough breathing mark,” and it only appears at the beginning of words.
Notice that the Greek word Χριστος begins with what looks like an X, the 24th letter of the English alphabet, but it’s really the Greek letter chi = Χ.
The late R.C. Sproul (1939-2017) writes that “the idea of X as an abbreviation for the name of Christ came into use in our culture with no intent to show any disrespect for Jesus.” Using a single letter to represent a title or name is not unusual. For example, the “R. C.” in R. C. Sproul stands for Robert Charles and is not meant to demean the man.
Most Christians are familiar with the use of the symbol of the fish as a way to represent Jesus Christ. The Greek word for fish in Greek is iχθύς (lower case letters) and ΊΧΘΥΣ (upper case letters). Each letter represents a Greek word that in abbreviated form describes the redemptive and relational work of Jesus: Ίησοῦς Χριστός Θεοῦ Υἱός Σωτήρ: (’Iēsous Christos Theou Yios Sōtēr) = “Jesus Christ, Son of God, Savior” or “Jesus Christ, God, Son, Savior.”
“The early Christians would take the first letter of each of those words and put those letters together to spell the Greek word for fish. That’s how the symbol of the fish became the universal symbol of Christendom,” Sproul writes.
Consider the use of X and P (the r sound in Greek) = Chi Rho. The Χ (Chi), as we’ve seen, is an abbreviation for Christ representing the first letter in the word Χριστός, and the letter “P” (Rho) represents the second letter in upper case form. What looks like a “P” to us is actually the Greek letter for “R.”