1 Cor 2:2 For I resolved to know nothing while I was with you except Jesus Christ and him crucified. NIV

1 Cor 1:23 but we preach Christ crucified: a stumbling block to Jews and foolishness to Gentiles, NIV

1 Cor 15:1-11 Now, brothers, I want to remind you of the gospel I preached to you, which you received and on which you have taken your stand. 2 By this gospel you are saved, if you hold firmly to the word I preached to you. Otherwise, you have believed in vain.
3 For what I received I passed on to you as of first importance: that Christ died for our sins according to the Scriptures, 4 that he was buried, that he was raised on the third day according to the Scriptures, 5 and that he appeared to Peter, and then to the Twelve. 6 After that, he appeared to more than five hundred of the brothers at the same time, most of whom are still living, though some have fallen asleep. 7 Then he appeared to James, then to all the apostles, 8 and last of all he appeared to me also, as to one abnormally born.
9 For I am the least of the apostles and do not even deserve to be called an apostle, because I persecuted the church of God. 10 But by the grace of God I am what I am, and his grace to me was not without effect. No, I worked harder than all of them-yet not I, but the grace of God that was with me. 11 Whether, then, it was I or they, this is what we preach , and this is what you believed. NIV

Paul preached the gospel which includes the death, burial and resurrection of Jesus.

1 Cor 4:17 For this reason I am sending to you Timothy, my son whom I love, who is faithful in the Lord. He will remind you of my way of life in Christ Jesus, which agrees with what I teach everywhere in every church. NIV

Paul (and Timothy the evangelist) taught a way of life that he also demonstrated in the way he himself lived.

2 Cor 4:5 For we do not preach ourselves, but Jesus Christ as Lord, and ourselves as your servants for Jesus' sake. NIV

Paul preached Jesus as Lord, but also his own (and Timothy's) role in Christ.

Acts 15:35-36 But Paul and Barnabas remained in Antioch, where they and many others taught and preached the word of the Lord.
36 Some time later Paul said to Barnabas, "Let us go back and visit the brothers in all the towns where we preached the word of the Lord and see how they are doing." NIV

Paul and Barnabus preached and taught the word of the Lord, at home and everywhere they went.

Acts 17:13 When the Jews in Thessalonica learned that Paul was preaching the word of God at Berea, they went there too, agitating the crowds and stirring them up. NIV

Paul preached the word of God.

Acts 18:5 When Silas and Timothy came from Macedonia, Paul devoted himself exclusively to preaching , testifying to the Jews that Jesus was the Christ. NIV

Paul preached that Jesus is the Christ (with the support of the Macedonian churches while he was in Corinth).

Acts 18:11 So Paul stayed for a year and a half, teaching them the word of God. NIV

Paul taught the word of God (in Corinth)

Acts 20:20 You know that I have not hesitated to preach anything that would be helpful to you but have taught you publicly and from house to house.
Acts 20:25 "Now I know that none of you among whom I have gone about preaching the kingdom will ever see me again. NIV

Paul preached (and taught) the kingdom, and anything that would be helpful to the church (as he said to the Ephesian elders about the time he spent in Ephesus).

Acts 26:20 First to those in Damascus, then to those in Jerusalem and in all Judea, and to the Gentiles also, I preached that they should repent and turn to God and prove their repentance by their deeds. NIV

Paul preached repentance and obedience to God, and he preached righteous living.

Acts 28:31 Boldly and without hindrance he preached the kingdom of God and taught about the Lord Jesus Christ. NIV

Paul preached the kingdom of God and taught about Jesus.

It is impossible to "know nothing ... except Jesus Christ" without preaching and teaching the full message of Christ, including the gospel of Christ which is the gospel of the kingdom (the church Jesus bought with his blood); including repentance and doing good deeds; including the roles and work of apostles, evangelists, and elders; including the life Paul taught and exemplified; including the word of God in its entirety. Paul elected not to preach things that come from human reasoning or philosophy, but rather to preach what was revealed by the Spirit and in the scriptures. It is still necessary to preach and teach the same, the 5th chapter of 1 Corinthians and the 9th as well as the 15th, for salvation and sanctification.