I have been asked both by a non-Christian friend and by Catholic friends what makes the writings in the bible stand apart and why are they regarded as the Word of God?
Very good questions. The answer is that all these writings, each of the different books which form the canon of the bible, have passed the three fold test of apostolicity, catholicity, consistency.
Big words, what do they mean?
Apostolicity: the writings are traceable for the new testament writings, directly back to the apostles. Either writen by the apostles themselves of direct disciples of the apostles.
Catholicity: "catholic" in its wider sense means "universal". The test of catholicity refers to widespread useage by the early church.
Consistency: that the content and teaching of the book do not contain anything which is inconsistent with other church tradition and doctrine.
Hence all the writings in the New Testament as we know it pass all these three tests. They have been historically traced by biblical scholars back to the apostles, known to be in widespread use by the early church as divinely inspired and all their teachings are consistent with each other. Note that the tests all have to do with chuch tradition. Church tradition is the basis for establishing the authenticity of the bible.
Next question: What about the old testament canon? Clearly they don't pass the test of apostolicity right? They were in existance long before the apostles as writings regarded by the Jewish people as coming from God. So is there an alternative test for apostolicity?