The greetings of "good luck" may have derived from "good fortune" or "be well." As you may know, when an actor goes to the stage the first time he is greeted by his fellow actors with "break a leg." While there is no specific meaning or hidden agenda behind this popular greeting, we Christians refrain from using the word luck, because as Jon-Mark said...
Jon-Mark said:There's no such thing as luck. My life is guided by the Holy Spirit and not by luck.