All believers are part of one body and are given different gifts for each other, all parts of the body of the church are needed and make up the body of Christ
All the apostles and many others are eye witnesses to the risen Christ, He was the first resurrected and all believers will one day receive a new resurrected imperishable body.
Paul argues that man's character is depraved with or without the law and that trading this sin nature inherited from Adam for Christ's righteousness by imputation is the best deal ever, and the only truth worth living for.
Apostles endure hardships for the cause of Christ this is a noble cause which benefits the Corinthian believers, believers and unbelievers should not be joined together.
Live gererously and graciously toward one another just like Jesus who became poor for all of our sakes, and show this love to Titus.
Paul responds to divisions in the Corinthian church based on misinterpretations of his teachings that kingdom rewards are not evident through gifts and success now , but that this is an age of suffering humbly for the gospel for future kingdom rewards.
Paul is being accused of being two faced therefore under a curse by not requiring circumcision for Galatians believers, Paul argues his gospel of imputed righteousness is the point of the Law fulfilled in Christ.