NOTES for Co2 13:1-14
Some members of the Corinthian community began to doubt that Christ was speaking through the apostle and demanded proof (2 Cor 13:3). What answer can be given to someone who doubts whether he (or another person—in this case, the apostle) is in Christ? What proof can there be apart from the assurance of faith itself?
If there is no malice (for one can doubt simply because one wants to doubt and does not want to know the truth), then we have a wonderful means of assurance: Jesus Christ is in us; through faith He has made His dwelling in our hearts (cf. Eph 3:17), and our spirit that lives by faith in Christ—the “inner person”—is our truest essence. Doubt in faith then appears as a betrayal of ourselves, of our innermost truth, when “we are not what we ought to be.”