Xmas is a valid expression, it derives from the clerical notation in Koine Greek XPmas (dating back to at least 1021 in this country). The XP relates to Chi-Ro the expression for Christos..so Xmas is to all intent and purposes perfectly valid in relation to Christianity, not to mention its symbolic connection to Christ which only underlines its literal meaning. In fact being as Christmas derives from a later Old English expression it predates the Anglo-Saxon word.
Technically using Xmas (and knowing its significance) makes you vastly more educated and cultured than using plain old Christmas....
