I bet you’re wrong. I bet this church really values the message of the REAL Jesus so much that they do not want the congregation distracted by a guy in a costume, who is only there for attention. What kind of Christian wants a bunch of attention on himself during a worship service? Not a Lutheran Christian, I guarantee you. I go to service to focus on the Jesus of the Bible, not for a show.
I'll say it once again in a little clearer fashion . . .
Anyone calling themselves Christian and going to a ‘Christian’ church shouldn't be pulled away from their worship by any individual that comes dressed in odd fashion, makes no commotion and participates quietly (all of which this fellow seems to have done). In fact, such a visitor should cause more than a little introspection in the heart of true believers - you know, the pharisee and sinner sort of thing.