Written as late as 100 A.D., John probably was the work of one of Jesus’ closest disciples. It may have been written earlier since it has some details that only a person would know who was living before Jerusalem was destroyed by the Romans in 70 A.D. It is the only gospel that is not considered synoptic (Matthew, Mark, and Luke) because of its major differences in miracles reported, lack of parables, unusual opening, order of events, the focus on the Jerusalem ministry, the literary style, and the material covered.
It is less of a biography and more of a meditation on the theological significance of Jesus. Christian morality is not the focus. Instead, we are introduced to Jesus the Messiah, Jesus the God-man. To prove this, John focuses on miraculous signs that Jesus provided. The key word is “believe,” which is found 98 times in the book. Like a drama, the book has a prologue (chapter 1) that introduces its themes, one act (chapter 2-12) that explains the revelation of God’s Word to the world through six signs (miracles), a second act (chapters 13-20) in which Jesus prepares death and resurrection, and an epilogue (chapter21). As you read the book, look for John’s attempts to prove his case for the divinity of Jesus.