Possible meanings are 1) "we persuade people of the truth of the gospel" or 2) "we persuade people that we are legitimate apostles." (See: [[rc://en/ta/man/translate/figs-explicit]])
This can be stated in active form. Alternate translation: "God clearly sees what kind of people we are" (See: [[rc://en/ta/man/translate/figs-activepassive]])