From On-line Etymology site:
1624, Hocas Pocas, common name of a magician or juggler, a sham-Latin invocation used in tricks, probably based on a perversion of the sacramental blessing from the Mass, Hoc est corpus meum "This is my body." The first to make this speculation on its origin apparently was Eng. prelate John Tillotson (1630-1694).
"I will speak of one man ... that went about in King James his time ... who called himself, the Kings Majesties most excellent Hocus Pocus, and so was called, because that at the playing of every Trick, he used to say, Hocus pocus, tontus tabantus, vade celeriter jubeo, a dark composure of words, to blinde the eyes of the beholders, to make his Trick pass the more currantly without discovery." [Thomas Ady, "A Candle in the Dark," 1655]
Just to further Crimthann's statements, I looked up the etymology of hocus-pocus. I am Christian and I have no problem with the "Hate the sin, not the sinner" statement, but I wonder if the good vicar who chided BFG1 realizes that some of the words of Jesus during the Last Supper would have been translated into the Latin from which hocus pocus comes. The vicar probably needed to brush up on his latin.
By the way, forgetting about whether it is geared toward a particular act, the saying "hate the sin, not the sinner" is in no way unChristian. Jesus despised sin. Even when someone was caught in sin, He said to them, "Go and sin no more." He never condoned sin in any form. However, he loved every last one of us human beings, even though we were imperfect. Even if a particular saying is not literally in the bible, it's not necessarily unChristian.
You may attack me for it, but it shows a remarkable lack of tolerance on anyone's part to say that you cannot love someone who sins and that is the natural extension to saying the phrase is just another form of hatred. What are the alternatives? I guess you can be consistent and say, "Hate the sin and the sinner," or perhaps you could say, "Who's to say what is sin, so don't hate anyone and accept everything that everyone does."
People do things that are wrong. What is wrong with having a standard that governs right and wrong. My son does a lot of things i really hate and, yes, they are sin...stealing a car, etc. I don't hate him. I love him. If you can prove to me that "hate the sin, not the sinner" is not in line with Christian theology...well...you can't prove that to me.