Who was the author? St. John the apostle was inspired by the Holy Spirit to write this book that bears his name.
What is the book? The book of John is an account of the Holy Gospel, or "good news", of Jesus Christ.
Where was it written? St. John is thought to have written this Gospel account from Ephesus, and the Gospel account is said to reflect some of the conflicts and temptations facing believers then, although those conflicts and temptations really face believers of all earthly times and places.
When was it written? There are two views of when St. John wrote, one that would suggest it was relatively early and independent of the other Gospel accounts, about A.D. 50-70, and the other more-usual conservative dating that puts the date after A.D. 85, possibly between 90-100, and assumes John knew of the other "synoptic" Gospel accounts (namely, Matthew, Mark, and Luke).
Why? St. John makes explicit his purpose for writing what he did in the Gospel account: "that you may believe that Jesus is the Christ, the Son of God, and that by believing you may have life in his name" (John 20:21). The "believe" may also be "continue to believe", making John's purpose winning and strengthening converts.
How? Unlike the other accounts, which tend to see Jesus's life with roughly the same eye, St. John's account is said to soar theologically higher than the others. John begins with a statement of his theme that is then unpacked in a spiral that rises higher and grows wider but often returns to the same points of emphases.
For further reading on the book of John:
- Lenski, R. C. H. The Interpretation of St. John's Gospel. Columbus, OH: Lutheran Book Concern, 1942. (This lengthy volume of 1444 pages, like the other Lenski commentaries, is a bit dated in terms of modern scholarship but nevertheless a good, helpful Lutheran commentary, one that you can find in Grace's library.)
- Ridderbos, Herman. The Gospel according to John: A Theological Commentary, tr. John Vriend. Grand Rapids, MI: William B. Eerdmans Publishing Company, 1997. (This commentary was used by the Rev. Dr. William Weinrich of the Ft. Wayne seminary when he taught the continuing education class in Austin a number of years ago. I have other John commentaries on my shelf that I also like, but this is the newest and, like the others, must be read with the special discretion needed for a book that comes from outside the Lutheran tradition.)