2 Corinthians 13:5-6 Examine yourselves, whether ye be in the faith; prove your own selves. Know ye not your own selves, how that Jesus Christ is in you, except ye be reprobates? 6 But I trust that ye shall know that we are not reprobates.

The word “reprobate” literally means “failing to meet the test”, that is, “of false profession of faith, proven false”. [Friberg] He posed this to the Corinthian Christians, under the influence of the enemies of the gospel, who sought to undermine his apostleship. He asked them to examine if their profession was false.

MacDonald observed well, “Paul is not telling the Corinthians to engage in self-examination as a proof of their salvation. Rather he is asking them to find in their salvation a proof of his apostleship.”

If they found that their faith in Jesus Christ in genuine, that Christ is living in them, then, the Apostle Paul’s ministry and that of his gospel team is therefore genuine and they should not be deemed disqualified as they have alleged.