Anyone who's ever taught a High School Religion course knows that at some point, that perennial question that has troubled theologians for centuries and continues to plague modern and post-modern young people will arise: "Do Dogs go to heaven when they die?" To answer this question positively is to give comfort and consolation to the fearful souls of students.
But God forbid you answer this question negatively. As one of my former students learned in his first year of teaching, to even suggest the possibility that dogs might not go to heaven (e.g., because they do not have immortal souls, or that they are not persons, or for some other reason)--much less to unequivocally declare that they do not--will arouse the wrath of students and the ire of their pet-loving parents (not to mention a potential trip to your supervisor's office for teaching such 'rigid' and 'disturbing' doctrines).
Up until now, when asked how to deal with this situation by students, I've simply suggested that they use reason (Hah!) and philosophy (double Hah!) to attempt to persuade the students that the longing to be with 'Fluffy' forever in the heavenly Jerusalem may in fact go unfulfilled.
However, I recently discovered that there is actual biblical evidence against dogs going to heaven. Well, this is entirely different. It's one thing to make a philosophical argument, but quite another to have Sacred Scripture on your side. So here it is. In the final chapter of the Bible, the Book of Revelation is describing the heavenly Jerusalem come down to earth, and in this context explicitly states:
Then he showed me the river of the water of life, bright as crystal, flowing from the throne of God and of the Lamb through the middle of the street of the city [the new Jerusalem]; also, on either side of the river, the Tree of Life... Blessed are those who wash their robes, that they may have the right to the Tree of Life and that they may enter the city by the gates. Outside are the dogs and sorcerers and fornicators and murderers and idolaters, and every one who loves and practices falsehood (Revelation 22:1-2, 14-15)
There you have it, in black and white! Even the Greek is clear: Outside are "the dogs" (kunes). The Heavenly Jerusalem has a sign, and it reads: "No Dogs allowed." So, for all you dog-lovers, sorry. Dog's don't go to heaven; the Bible says so; that settles it. Whatever you may hope for, you won't be seeing Rover in the New Jerusalem.
P.S. I might note in closing that this brings me no particular grief. I'm a cat person, and of cats being excluded from heaven the Bible says nothing.
P.P.S. It might have helped the now-famous church sign debate over the issue for somebody to actually proof-text Scripture. That is, after all, the usual exegetical method of such signs.