John's Hermeneutical Principle

"Interpreters have noted that the evangelist gives the reader important hermeneutical guidance for understanding his Gospel, including its sacramental teaching, after the account of the cleansing of the temple in chapter two, where he states: “When, therefore, [Jesus] was raised from the dead, his disciples remembered that he had said this; and they believed the Scripture and the word which Jesus had spoken” (John 2:22).7 Even as the original hearers of Jesus did not understand some of his teaching about his death and resurrection until after the resurrection (e.g., “Destroy this temple and in three days I will raise it up” in John 2:19), so also they did not understand some of his teaching about the sacraments until after the resurrection and ascension when the sacraments began to play a very significant role in mediating the presence and forgiveness of Jesus. If one understands Jesus’ discourses in this Gospel as sermons that John delivered to the post-Easter church that was baptizing people and celebrating the Lord’s Supper weekly, then it is easier to understand how these discourses communicate about the sacraments."

Charles A. Gieschen, "Baptism and the Lord’s Supper in the Gospel of John", CTQ 78-1,2