Readings on the First Epistle of John

In taking up the study of the first epistle of John, a comparison of John's ministry with that of Peter and Paul will be helpful.
The words addressed to Peter in John 21: 18, 19 imply that in some sense his ministry was to have a character similar to that of the Lord Jesus. Is the implication supported by Scripture elsewhere? If so, in what sense was Peter's ministry similar to the ministry of Jesus Christ?
Light is shed on these questions in Romans 15: 8 and Galatians 2: 7, 8. In the former passage Jesus Christ is called a "minister of the circumcision," the evident meaning being that His ministry was in connection with the people in the covenant of circumcision — that made with hands. In the latter passage there is mention of "the gospel of the circumcision" as having been committed to Peter. The thought evidently is that a gospel specially addressed to the circumcision was committed to Peter. Peter is also spoken of as having the "apostleship of the circumcision." Undoubtedly the intention is to show that Peter exercised apostleship in connection with the circumcision. In this sense, then, Peter's ministry was similar to that of Jesus Christ.
But while this marks out the people for whom his ministry is intended, it does not define its theme and character, which are to be inquired into. If we refer again to Romans 15: 8 we shall find it stated there that "Jesus Christ was a minister of the circumcision for the truth of God, to confirm the promises made unto the fathers: and that the Gentiles might glorify God for His mercy." This needs to be carefully considered.