I was reading the Gospel of St. John last night and I was on chapter 6--the part where Jesus is discussing the Eucharist. Anyhow, I noticed John 6:66, which says "From that time many of His disciples went back and walked with Him no more. " and the passage was referring to when people left Him behind because they could not understand the Mystery of the Eucharist. Does the legendary "666" of Revelation refer to this passage in John--to this apostating because you cannot understand the Eucharist? If so, does this mean that Protestants who do not accept the literal presence of the Eucharist and reject the Orthodox Church because of it are bearing the mark of the beast?