Paul preached "Jesus Christ as Lord, and ourselves as your servants for Jesus' sake" (2Co 4:6) whereby "through us spreads everywhere . . . the knowledge of him" (2Co 2:14). Furthermore, "in Christ we speak before God with sincerity, like men sent from God (v.17)." He was sent to "preach the gospel-not with words of human wisdom" (1Co 1:17) but to "preach Christ crucified" (:23). He "did not come with eloquence or superior wisdom [but with] the testimony about God" (1Co 2:1). He "received from the Lord" (1Co 11:23) and "what I received I passed on to you as of first importance" (1Co 15:3). Paul was committed to this "field God has assigned to us, a field that reaches even to you" (2Co 10:13). He did "have knowledge [and] made this perfectly clear to you in every way" (2Co 11:6).
The result of Paul's ministry was that "our testimony of Christ was confirmed in you" (1Co 1:6) in that God "has called you into fellowship with his Son" (:9). This applies to "all those everywhere who call on the name of our Lord Jesus Christ" (:2) because they are "sanctified in Christ Jesus and called to be holy" (:2). Paul sought to reach everyone "so that by all possible means I might save some" (1Co 9:22). He was "not seeking my own good but the good of many, so that they might be saved" (10:33). He saw "the message of the cross . . . to us who are being saved [as] the power of God" (1Co 1:18). He observed that "God was pleased through the foolishness of what was preached to save those who believe" (:21). He considered himself as a servant "through whom you came to believe" (1Co 3:5). Believing is the key. Paul reminded them that "the gospel I preached to you, which you received and on which you have taken your stand [is how] you are saved" (1Co 15:1-2).
The Corinthian church was "enriched in every way" (1Co 1:4) yet still had problems. You would think that with the help of the Apostle Paul they wouldn't "sit in judgment" (1Co 9:3) of him. He was concerned that "when I come I may not find you as I want you to be" (2Co 12:20). Yet he was concerned that "your minds may somehow be led astray" (:3). You have to be careful what you tolerate in your mind because "a little yeast works through the whole batch" (1Co 5:6). They were susceptible because Paul said "you put up with it easily enough" (2Co 11:4). But it is dependent on that "you hold firmly to the word I preached [or else] you have believed in vain" (:2). It is a continuing process as you are "among those who are being saved" (2Co 2:15).