[CynicalBear]

If you were following the discussion you would have known we were talking about the passage in Matthew 16 not John 1.

[Salvation]

Changing a name indicates a changed person. This is a moment of great significance for Peter. "Kephas" is the Greek transcription of an Aramaic word meaning stone, rock. It is not a proper name, but Jesus gave it to Simon to indicate his role as his vicar, which he will later on reveal (Mt 16:16-18): Simon was destined to be the stone, the rock of the Church. We might say today he was to become a "pillar" or "cornerstone".