Grisham is certainly correct in his message.  The celebration of Christ-mas is not about Santa and making sure that the economy of the business world ends the year in the black.  His efforts to remind the world of this is consistent with his chosen profession as a Pastor.

However his methods are what are troubling.  They are the same as the majority of TV Evangelists, which are to focus people on them and not the words in the Bible.  To go to a 'santa' line and hand out reminders about christmas or to even speak politely to the parents about their religious beliefs are a worthy activities for his ministry, but to openly confront parents and distress their children loudly in public is nothing but confrontational.  Jesus was only confrontational to the money changers in the temple.

No, Grisham is not Isaiah or a prophet, he is a celebrity wannabe doing his best to give true Christianity a bad rap.  The message is sound and truthful, his chosen methods and reasons are not.