PSA to Christians: “X-mas” is not removing Christ from Christmas.

The “X” is not a Roman letter, but the Greek letter Chi, as in Χρίστος (Christ). It’s the same reason you see that symbol of the P with the X on the stem, because they represent Chi and Rho, the first two Greek letters in Christ. (Edit: ☧)

In short, “X-mas” is not an erasure of Christ. Rather, it is merely an abbreviation of Χρίστος.