It's in one of the Papal encyclicals, I think. Humanae Vitae.
(It was Gaudium Et Spes 22. Heh. Silly me.)
Considering the Bible has over two-dozen authors, has been translated through half a dozen languages, rewritten multiple times over the last two thousand odd years and the parts relating to Jesus were written and compiled approximately 200 years after his supposed death, it's a minor miracle it has any consistancy at all.
I think they've determined that the first three gospels were written only about 40 years after he died, especially since the first one (Mark) makes no references to the destruction of the temple, while the other two (Luke and Matthew) do. I think the stuff like Acts and Revelations were written a fair bit after as well.
The compilation itself, yes, wasn't until a couple hundred years after.
You can put the inconsistencies in Luke and Matthew down to the fact that they definitely added a lot of stuff that wasn't in Mark - the Nativity, among other things. Matthew has different miracles I think (I'll have to recheck), and has the Sermon on the Mount while Luke has the Sermon on the Plain.
Why am I ignoring the gospel of John? Because he was a self-aggrandizing little arse.