The "X" is the Greek symbol for “Christ” (think Christmas = Xmas). The “X” is actually a representation of the Greek letter “Chi,” which is short for the Greek word "ΧΡΙΣΤΟΣ", meaning “Christ. The Greek letters “X” (Chi) and “p” (Rho) superimposed together was once a very common symbol of Christ and was called the Chi-Rho. Is one of the earliest forms of christogram, and is used by some Christians. It is formed by superimposing the first two (capital) letters chi and rho (ΧΡ) of the Greek word "ΧΡΙΣΤΟΣ" = Christ in such a way to produce the monogram. Although not technically a Christian cross, the Chi-Rho invokes the crucifixion of Jesus, as well as symbolising his status as the Christ.