People seem to express chagrin about seeing Christ’s name dropped and replaced by this symbol for an unknown quantity X. 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.This is interesting and helpful, but I still suspect that a lot of people use Xmas to avoid writing Christmas and have no idea what the etymology of the word is. In any case, Sproul goes on to explain the origin of the fish as a symbol for Christianity:
First of all, you have to understand that it is not the letter X that is put into Christmas. We see the English letter X there, but actually what it involves is the first letter of the Greek name for Christ. Christos is the New Testament Greek for Christ. The first letter of the Greek word Christos is transliterated into our alphabet as an X. That X has come through church history to be a shorthand symbol for the name of Christ....There’s a long and sacred history of the use of X to symbolize the name of Christ, and from its origin, it has meant no disrespect.
The church has used the symbol of the fish historically because it is an acronym. Fish in Greek (ichthus) involved the use of the first letters for the Greek phrase “Jesus Christ, Son of God, Savior.” So the early Christians would take the first letter 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.If you already knew all this you have VP's permission to feel pleased with yourself. If you didn't know it before, now you do.