Q. I have a question that I thought was straightforward but seems to be a point of discussion even among bible scholars. Who was the most prolific writer in the New Testament? I always thought it was Paul, but I heard a well-respected pastor say it was Luke. When I researched the answer online, there seemed to be some debate. How can this be? It seems to me that a person could count the words, chapters, or books written by each and come up with a definitive answer. Why the confusion? Who does deserve the credit?
As I understand it, Luke is the writer responsible for the largest part of the New Testament. This is if we go by word count, i.e. “by volume.” I think that’s more accurate than by book, chapter, or verse, as these can vary greatly in length. (This is true even if Paul wrote Hebrews, which I think is doubtful, but which many believe on the basis of tradition.)
In other words, Luke-Acts (originally written as a single work, though divided and separated in most Bibles) is by itself longer than all thirteen of Paul’s letters combined. You can get a rough idea of this by counting the pages, especially in an edition that has no headings or chapter numbers, like The Books of the Bible (in which Luke-Acts is also restored to unity as a single work). In that edition, Luke-Acts is 99 pages while Paul’s letters are 97 pages–and that number is inflated by the blank space frequently left on the last pages of his many letters. Luke-Acts only has one “last page,” and its page count suffers accordingly. But once again, if we go by words, we discover that Luke actually wrote the largest part of the New Testament.
Good Question 
The Holy Spirit deserves the credit, not the writers. I don’t mean to be technical, but all scripture is given by the inspiration of the Holy Spirit, and one is required to correctly know what is of man and what is of the Spirit. So, we are called to correctly divide the word of Truth, comparing spiritual things with spiritual things. In effect, you have to have a relationship with the Spirit of Truth, and the Spirit of Truth will teach you Truth through His Word, contained in the Bible. So, it does not matter who wrote most of the New Testament. What does matter is that you are able to discern Truth in Scripture. You need to know the Teacher’s method of dividing the Word, because after all, He is the Word and the Teacher of His Word, being the ‘Helper’, the ‘Teacher’ and the ‘Comforter’. If He is not the ‘Cornerstone’ of His Understanding only He can give, there is an ‘angel of light’ that poses as the Holy Spirit, to lead one into confusion. Normally those who say that there are contradictions in the New Testament, are not experienced in dividing the Word of Truth, or even having a relationship with the Teacher Himself. Anyone who disagrees with this response is a liar because we are called to lead others to His Living Spirit, and not what they have to say, or teach. Every believer must lead you to the Teacher. So, I suggest, give the Teacher credit and seek that He teaches you as He taught Luke, Paul, James, etc. One has to KNOW the consensus between what Paul says, what James says, what Luke says and what any other Prophet says BY THE SPIRIT. So then, walk in the Spirit, so that you do not fulfil the lusts of the flesh. One of the greatest lusts of the flesh is to put all confidence in the flesh so that by the flesh one understands the letter. The letter kills but the Spirit gives life. If you are not prepared to have the Teacher Spirit teach you His Word Himself, what you read and study in the Bible can actually block you up and make you a religious Pharisee. So please take your eyes off the writers, and get to the Spirit who gives inspiration.
dude. relax. let the man write a blog without you going all righteous on him and becoming judgey mcjudger pants. your response reads like that guy who comes into an awesome bible study, but then ruins the mood, by not listening to anyone, but hijacks the conversation to regurgitate something his pastor preached 5 years ago. relax, my brother and enjoy the ride.
Luke wrote rather like a historian records events. Luke work in that was immensely important. However, perhaps a better question might be who did the most teaching in the NT. And I think that would be Paul.