John Calvin Commentary 2 Corinthians 1:1

"Paul, an apostle of Christ Jesus through the will of God, and Timothy our brother, unto the church of God which is at Corinth, with all the saints that are in the whole of Achaia:" — 2 Corinthians 1:1 (ASV)

Paul an Apostle. Regarding the reasons why he designates himself an Apostle of Christ, and adds that he has obtained this honor by the will of God, see the previous Epistle. There, it was observed that we should listen only to those who have been sent by God and speak from his mouth. Consequently, to secure authority for anyone, two things are required: a call, and fidelity on the part of the person who is called in the execution of his office.

Paul claims both of these for himself. The false apostles, it is true, do the same; but by usurping a title that does not belong to them, they gain nothing among the sons of God, who can with the utmost ease convict them of presumption. Therefore, the mere name is not enough if the reality is not present along with it, so that he who presents himself as an Apostle must also show himself to be such by his work.

To the Church of God. We must always keep in mind his recognition that a Church existed where there was such a multitude of evils. For the faults of individuals do not prevent a society that has genuine marks of religion from being recognized as a Church. But what does he mean by the expression with all saints? Were those saints unconnected with the Church? I answer that this phrase refers to believers who were dispersed here and there, in various parts of the province—it is likely that in that greatly disturbed period, when the enemies of Christ were everywhere venting their rage, many were scattered abroad who could not conveniently hold sacred assemblies.