[T]he apostle Paul (who wrote a large portion of the New Testament) writes to his fellow Christians that “if Christ has not been raised, your faith is futile; you are still in your sins.” (1 Cor 15:17)
If Jesus was not really raised, the Christian faith is actually a Christian farce; or, as historian Hugo Staudinger put it, if the New Testament writings “are really only tales which have been made up,” then “they can quite legitimately be replaced by other tales.” The idea that a person could retain their Christian faith while claiming that Jesus was not raised from the dead contradicts historic Christianity. And we learn about what Christianity is from the New Testament documents.
If the texts that comprise the Bible are unreliable, Christianity loses its foundation, says University of St. Andrews New Testament scholar Richard Bauckham, because “Christian faith has trusted that within these texts we encounter the real Jesus, and it is hard to see how Christian faith and theology can work with a radically distrusting attitude to the Gospels.”
Our primary record of the Christian faith is the New Testament; the New Testament texts serve as the foundation for accurate knowledge and belief about Jesus. The authors of the New Testament claimed to be writing true accounts of the life of Jesus, and the historical reliability of their writings is important because it protects the Christian faith from modern revisionism.
Our duty, then, is to investigate whether or not the New Testament documents are in fact accurate, and it is the intent of this analysis to demonstrate why we can be confident that the New Testament is historically reliable, that is, accurately preserved according to the original documents and reliable according to the sort of traditional tests applied to historical documents.
The question we are seeking to answer is Can we have confidence that the New Testament was accurately recorded and transmitted to us, and that what it contains is the product of early and eyewitness testimony?– Source: Darren Hewer, The Historical Reliability of the New Testament