John 52:54 is a Bible verse inscription found on an exterior wall at the murder scene of Garret Lorey. It is written in Mr. Lorey's blood and quoted by Mulder as, "He who eats of my flesh and drinks of my blood shall have eternal life. I will raise him up on the last day." Mulder goes on to say that whoever wrote this has a "feeble literal grasp of the bible as all those big-haired preachers do." (TXF: "3")
It's worth noting that this verse reference is actually incorrect. The proper verse quoted is John 6:54. John 52:54 does not exist.