John 1:40-42 says, One of the two who heard John speak, and followed Him, was Andrew, Simon Peter’s brother. 41 He first found his own brother Simon, and said to him, “We have found the Messiah” (which is translated, the Christ). 42 And he brought him to Jesus.
Now when Jesus looked at him, He said, “You are Simon the son of Jonah. You shall be called Cephas” (which is translated, A Stone).
When Peter was introduced to Jesus, the Spirit of God gave him a new name and a new nature. Peter was adopted by the Spirit through Jesus Christ into the Kingdom of God. When anyone comes to Jesus they are brought out of the old nature into the new.