While the Bible is certainly divinely inspired, including the New Testament Letters, it is important to remember that each book is written by a person.
Each of these people have their personal perceptions and way of expressing their understanding of Jesus Christ and the significance of his life and sacrifice. Certainly these authors agree overall in terms of theology, but how they express their understanding does vary due to the human element of their writings.
Other factors that influence their writings include the audience who was intended to receive their letter. Paul, for example, often speaks of specific subjects that relate directly to issues arising in the churches he wrote, such as Corinthian's various issues with people living in sinful situations.
Also important, is to understand that these particular “books of the Bible” are actually letters, originally with no chapter or verse numbers. They were letters written to believers and intended to be read in one sitting, just like a letter or email we might write. The audience would have likely gathered together, and the letter would have been read out-loud, all at once.
Also, like letters we might write, each author has an entire stream of thought that often extends throughout the entire letter; meaning one major explanation may extend throughout the entire book, with mini-explanations within the larger one lasting for chapters (especially in Paul's longer letters).
The importance of understanding that these books are letters (intended to be read all at once), is that many verses are regularly taken out of context and used to contradict what the author is actually saying, creating incorrect theology and beliefs.
Essentially, someone may teach about a verse that Paul writes, whereas Paul makes other statements that contradict what is being taught, because the verse is taken out-of-context and used to mean what it does not mean.
The letter of Romans, in particular, falls victim to many people taking its verses out-of-context and wrongly using them for beliefs that Paul himself contradicts in Romans and his other letters in the New Testament.
The following is a list of the New Testament letters, with each book being summarized according to chapters to make the overall point of each letter apparent. Also provided is a concluding summary of the letter itself.