Chapters 1-7
The Introduction of the Epistle
Vss. 1-2—Even though Paul was an apostle, he includes Timothy in his salutation. Mentioning Timothy does not mean that he was the co-author of the letter, but that he attested to Paul’s remarks to the Corinthians. This was because he was addressing an assembly, and all things on that corporate level are to be done “in the mouth of two or three witnesses” (2 Cor. 13:1; John 8:17).
Paul calls himself an apostle of “Christ Jesus” because that expression denotes Christ as having completed redemption and gone back into heaven as a glorified Man. It was from Christ on high in the glory that Paul had received his apostleship (1 Cor. 9:1-2). In each of his epistles, when mentioning his apostleship, he speaks of having received it from “Christ Jesus.” (The KJV does not make this distinction, but most critical translations and interlinear translations do.) Peter, on the other hand, calls himself an apostle of “Jesus Christ” (1 Peter 1:1; 2 Peter 1:1). This expression denotes Christ as the One who came from heaven to accomplish the will of God, and it was here when the Lord was on earth that Peter received his apostleship (Luke 6:13-16).
The epistle is addressed to “the church [assembly] of God which is at Corinth, with all the saints which are in all Achaia.” “Saints,” as mentioned here, does not denote moral perfection, as commonly thought, but those who have been set apart by the work of God in new birth. “Saint,” means a set apart one. It carries the thought of being made holy, because such have been set in a clean place with a holy nature, and they are there by divine calling. A saint, though separated to God through a divine work, in practice may be quite unholy in his or her doctrine and walk. This, sad to say, was the case of the assembly at Corinth. Paul addressed them as being "saints" in both of the epistles to them, yet they were going on with some very unholy doctrines and practises. It shows that the term refers to a person's position before God, not their practical state.
“Grace” and “peace” are mentioned as being supplied from “God our Father and from our Lord Jesus Christ.” He gives grace for our needs in the way and peace for all circumstances we encounter.
The Characteristics of a True Minister of Christ
Attacked by certain critics, Paul now presents a grand defence of his life and ministry. As he explains his movements in the service of the Lord, he removes the misgivings and suspicions that were lodged in the minds of the Corinthians by his opposers. He exposes the deceit and absurdity of the false claims levelled at him in a careful and methodical way, showing the Corinthians that those criticisms were unfounded.
As mentioned, as he does this, he presents a character sketch of what a true minister of God ought to be. This would give the Corinthians a standard by which they could discern all who would come to them and present themselves as ministers of the Word, and it also provides us with an outline of what ought to characterize us as ministers of Christ.