For if he who comes preaches another Jesus whom we have not preached, or if you receive a different spirit which you have not received, or a different gospel which you have not accepted—you may well put up with it! For I consider that I am not at all inferior to the most eminent apostles. Even though I am untrained in speech, yet I am not in knowledge. But we have been thoroughly manifested among you in all things.
I think that Paul is assuring the saints of Corinth that he has been careful to teach the true Gospel to them. That even though another Jesus is preached with superior glibness, or a more attractive gospel, he, Paul, can be trusted to have correct knowledge.
Morning Psalm 9, Noon Psalm 119:113-120, Evening Psalm 100