"But these are written, that ye might believe that Jesus is the Christ, the Son of God; and that believing ye might have life through his name."
John 20:31 · King James Bible
What it is
The Gospel according to John is the fourth Gospel — the one written last, and the one that stands a little apart from the other three. It is the beloved disciple's testimony. It is short (twenty-one chapters), tender, direct, and it has been the entry point into Christianity for more people than any other book in the New Testament. The Church has always given a new Christian John to read first.
How to think of the shape
John's shape is beautifully simple. Chapter 1 is the prologue — 'In the beginning was the Word.' Chapters 2–12 are the book of signs — seven miracles chosen to reveal who Jesus is. Chapters 13–17 are the upper-room discourse — Jesus's last long conversation with his disciples, ending in his prayer for them. Chapters 18–20 are the passion and resurrection. Chapter 21 is the epilogue on the shore of Galilee — breakfast, forgiveness, and 'follow me.'
The seven signs
1. Water to wine at Cana (2)
2. The healing of the nobleman's son (4)
3. The healing at the pool of Bethesda (5)
4. The feeding of the five thousand (6)
5. Walking on the sea (6)
6. The healing of the man born blind (9)
7. The raising of Lazarus (11)
The seven 'I am' sayings
1. I am the bread of life (6:35)
2. I am the light of the world (8:12)
3. I am the door (10:9)
4. I am the good shepherd (10:11)
5. I am the resurrection, and the life (11:25)
6. I am the way, the truth, and the life (14:6)
7. I am the true vine (15:1)
How to read it as a household
John reads well in one large evening (three hours aloud) or over three weeks (one chapter a night). If a young family is starting: read John 1, John 3, John 6, John 11, John 14, John 20 — six evenings. That is the spine of the Gospel.
Why John wrote it
John himself tells you, near the end: "But these are written, that ye might believe that Jesus is the Christ, the Son of God; and that believing ye might have life through his name" (20:31). That is the whole aim of the book. Read it with that verse open.