Thegrastay, btw, regarding the Vatican, one thing that's commonly misunderstood, by Catholics and non-Catholics alike, is that 99% of what the Vatican says is not final. Most of what the Vatican says is about as definitive as what any given pastor says - it's a religious leader making a statement about something. Now, what I referenced is in that 1% however. It was a decision made over 3 years of debates among hundreds of church leaders from around the world and it is a statement as to what the Catholic Church stands for in the same way as Luther's Catechism can be looked at as a statement to what he believes Christianity ought to stand for.
As I was walking back to my dorm room, I thought of a great example of the difference between relatavism and what the Catholic Church holds to be true. If you look at Buddhism and the teachings of the Buddha, one cannot tell me (at leat if you're Christian) with any sense of validity that the Holy Spirit didn't speak through the Buddha. Go pick up a copy of <a href="http://www.amazon.com/exec/obidos/tg/detail/-/1569751692/102-4612298-9136145?v=glance">"Jesus and Buddha: The Parallel Sayings"</a> by Biblical scholar Marcus Borg and it's there pretty much in black and white. The Buddha felt God when he became enlightened and good Buddhists feel God as well as they become full of compassion, serenity, and tolerance. In that way, Buddhism has some of the Turth of God in it. But that's not to say that Buddhism is equally as valuable as Catholicism in the view of the Catholic Church. The whole point is that, fundamentally, Buddhism comes from the same source as Christianity, but it is not perfect. It ignores the idea of a higher power among other things. However, the core teachings of Buddhism teach people to be loving, compassionate people, just as the teachings of Christianity do. In that way, God is speaking through both, while the Fullness of God's will may only be found in the Catholic Church (so they say). Buddha may have not called what he felt the word "God," but he felt Him nonetheless and, thus, he can be saved through Jesus. Hope that was a little more clear.
I don't think any religion can have any validity if it says some other faith is equally valuable. What's the point in believing in a religion if you can say you'd be just as well off believing in another religion? Catholicism doesn't say that. Likewise, I don't think any Christian religion is valid if it says that God is one who would say "you were a model human being but since you didn't specifically believe in Jesus as your savior I'm sorry but you're not saved." Catholicism doesn't say that either.