John explains his aims in the writing of his Gospel, and explains the background of Jesus' "I Am" statements. He briefly discusses each of those seven statements.
Lazarus tells of seven miraculous signs of Jesus. Lazarus became the last of those signs when Jesus raised him from the dead.
Philip tells of the Last Supper, and gives his take on the famous parable of the Vine and Branches.
Joseph of Arimathea tells his view of the last day of the life of Jesus, and how he obtained the body and buried it.