In these verses observe,

I.The apostle threatens to be severe against obstinate sinners when he should come to Corinth, having now sent to them a first and second epistle, with proper admonitions and exhortations, in order to reform what was amiss among them. Concerning this we may notice, 1. The caution with which he proceeded in his censures: he was not hasty in using severity, but gave a first and second admonition. So some understand his words (Co2 13:1): This is the third time I am coming to you, referring to his first and second epistles, by which he admonished them, as if he were present with them, though in person he was absent, Co2 13:2. According to this interpretation, these two epistles are the witnesses he means in the first verse, referring rather to the direction of our Saviour (Mat 17:16) concerning the manner how Christians should deal with offenders before they proceed to extremity than to the law of Moses (Deu 17:6; Deu 19:15) for the behaviour of judges in criminal matters. We should go, or send, to our brother, once and again, to tell him of his fault. Thus the apostle had told these Corinthians before, in his former epistle, and now he tells them, or writes to those who heretofore had sinned, and to all others, giving warning unto all before he came in person the third time, to exercise severity against scandalous offenders. Others think that the apostle had designed and prepared for his journey to Corinth twice already, but was providentially hindered, and now informs them of his intentions a third time to come to them. However this be, it is observable that he kept an account how often he endeavoured, and what pains he took with these Corinthians for their good: and we may be sure that an account is kept in heaven, and we must be reckoned with another day for the helps we have had for our souls, and how we have improved them. 2. The threatening itself: That if (or when) he came again (in person) he would not spare obstinate sinners, and such as were impenitent, in their scandalous enormities. He had told them before, he feared God would humble him among them, because he should find some who had sinned and had not repented; and now he declares he would not spare such, but would inflict church-censures upon them, which are thought to have been accompanied in those early times with visible and extraordinary tokens of divine displeasure. Note, Though it is God's gracious method to bear long with sinners, yet he will not bear always; at length he will come, and will not spare those who remain obstinate and impenitent, notwithstanding all his methods to reclaim and reform them.

II.The apostle assigns a reason why he would be thus severe, namely, for a proof of Christ's speaking in him, which they sought after, Co2 13:3. The evidence of his apostleship was necessary for the credit, confirmation, and success, of the gospel he preached; and therefore such as denied this were justly and severely to be censured. It was the design of the false teachers to make the Corinthians call this matter into question, of which yet they had not weak, but strong and mighty proofs (Co2 13:3), notwithstanding the mean figure he made in the world and the contempt which by some was cast upon him. Even as Christ himself was crucified through weakness, or appeared in his crucifixion as a weak and contemptible person, but liveth by the power of God, or in his resurrection and life manifests his divine power (Co2 13:4), so the apostles, how mean and contemptible soever they appeared to the world, did yet, as instruments, manifest the power of God, and particularly the power of his grace, in converting the world to Christianity. And therefore, as a proof to those who among the Corinthians sought a proof of Christ's speaking in the apostle, he puts them upon proving their Christianity (Co2 13:5): Examine yourselves, etc. Hereby he intimates that, if they could prove their own Christianity, this would be a proof of his apostleship; for if they were in the faith, if Jesus Christ was in them, this was a proof that Christ spoke in him, because it was by his ministry that they did believe. He had been not only an instructor, but a father to them. He had begotten them again by the gospel of Christ. Now it could not be imagined that a divine power should go along with his ministrations if he had not his commission from on high. If therefore they could prove themselves not to be reprobates, not to be rejected of Christ, he trusted they would know that he was not a reprobate (Co2 13:6), not disowned by Christ. What the apostle here says of the duty of the Corinthians to examine themselves, etc., with the particular view already mentioned, is applicable to the great duty of all who call themselves Christians, to examine themselves concerning their spiritual state. We should examine whether we be in the faith, because it is a matter in which we may be easily deceived, and wherein a deceit is highly dangerous: we are therefore concerned to prove our own selves, to put the question to our own souls, whether Christ be in us, or not; and Christ is in us, except we be reprobates: so that either we are true Christians or we are great cheats; and what a reproachful thing is it for a man not to know himself, not to know his own mind!

Examine yourselves, whether ye be in the faith - Ἑαυτους πειραζετε· Try yourselves; pierce your hearts; bore yourselves throughout; try yourselves by what I have written, and see whether ye retain the true faith of the Gospel.

Prove your own selves - Ἑαυτους δοκιμαζετε· Put yourselves to the test, as you would try gold or silver suspected of adulteration. No more take that for Gospel which is not so, than you would take adulterated money for sterling coin. This is a metaphor taken from testing or assaying adulterated metals.

Know ye not your own selves - Are ye not full of wisdom and understanding? And is it not as easy to find out a spurious faith as it is to detect a base coin? There is an assay and touchstone for both. If base metal be mixed with the pure you can readily detect it; and as easily may you know that you are in the faith as you can know that base metal is mixed with the pure. Does Jesus Christ dwell in you? You have his Spirit, his power, his mind, if ye be Christians; and the Spirit of Christ bears witness with your spirit that ye are the children of God. And this is the case except ye be reprobates; αδοκιμοι, base counterfeit coin; mongrel Christians. This metaphor holds excellently here. They had a Judaizing Christian among them; such, presumptively, was the false apostle: they had received his Judaico-Christian doctrine, and were what the prophet said of some of the Israelites in his time. Reprobate silver, adulterated coin, shall men call them, Jer 6:30. And thus, when they were brought to the test, they were found reprobate; that is, adulterated with this mixture of bad doctrine. There is no other kind of reprobation mentioned here than that which refers to the trial and rejection of adulterated coin; and, by way of metaphor, to the detection of false Christianity. This reprobation came of the people themselves: they, not God, adulterated the pure metal. Man pollutes himself; then God reprobates the polluted.

Since ye seek a proof of Christ - The conversion of the Corinthians was to themselves a solid proof that Christ spoke by the apostle; and therefore he could, with great propriety, say that this power of Christ, far from being weak, was mighty among them.

Examine yourselves whether ye be in the faith,.... These words are to be considered in connection with Co2 13:3 for seeing they sought and demanded a proof the voice and power of Christ in the apostle, he directs them to self examination, to look within themselves, to try, prove, and recognise their own souls; where if things were right, they would find a proof of Christ's speaking in him, to them: he advises them to examine the state of their own souls, and see whether they were in the faith; either in the doctrine of faith, having a spiritual and experimental knowledge of it, true love and affection for it, an hearty belief of it, having felt the power of it upon their souls, and abode in it; whether, as the Syriac version reads it, , "ye stand in the faith", firm and stable; or in the grace of faith, either of miracles, or that which is connected with salvation; and which if they were in it, and had it, is attended with good works; operates by love to Christ and to his people; by which souls go out of themselves to Christ, live upon him, receive from him, and give him all the glory of salvation: and if this was their case, he desires to know how they came by their faith; and suggests, that their light in the doctrine of the Gospel, and their faith in Christ Jesus, as well as the miraculous gifts many of them were possessed of, were through his ministry as the means; and this was a full proof of Christ's speaking in him:

prove your own selves. Know ye not your own selves, how that Jesus Christ is in you; by which he means, that if they took a survey of things in their own souls, it would appear that Christ was in them; not as he is in all the world, filling heaven and earth with his presence; or as he is in every rational creature, as the Creator and author of the light of nature; but in a special and spiritual manner, by his Spirit and grace; the Father reveals him in his people, as the foundation of their hope of glory; he himself enters and takes possession of their hearts in conversion, communicates his grace, and manifests himself, and is formed there by his Spirit; his graces are implanted, his image is stamped, his Spirit is put within them, and he himself dwells by faith: and this upon inquiry would be found to be the case of the Corinthians,

except, says the apostle,

ye are reprobates; meaning not that they were so, as such may stand opposed to the elect of God; for persons may as yet neither be in the faith, nor Christ in them, and yet both be hereafter, and so not be left of God, or consigned to destruction; but that if they were not in the doctrine of, faith, then they were reprobate concerning it, or void of judgment in it; and if they had not the grace of faith, and Christ was not in them, then they were not genuine, but nominal professors, like "reprobate silver", counterfeit coin; which when detected, would be "disapproved", not only by God, but man, as this word also signifies, and so stands opposed to them that are "approved", Co2 13:7 or if they did not make such an examination, probation, and recognition of themselves, they would be without probation: or as the Arabic version, without experiment. The apostle hereby brings them into this dilemma, either that if upon examination they were found to be in the faith, and Christ in them, which blessings they enjoyed through his ministry, then they did not want a proof of Christ speaking in him; but if these things did not appear in them, then they were persons of no judgment in spiritual things, were not real Christians, but insignificant and useless persons.

Examine--Greek, "Try (make trial of) yourselves."

prove your own selves--This should be your first aim, rather than "seeking a proof of Christ speaking in me" (Co2 13:3).

your own selves--I need not speak much in proof of Christ being in me, your minister (Co2 13:3), for if ye try your own selves ye will see that Christ is also in you [CHRYSOSTOM], (Rom 8:10). Finding Christ dwelling in yourselves by faith, ye may well believe that He speaks in me, by whose ministry ye have received this faith [ESTIUS]. To doubt it would be the sin of Israel, who, after so many miracles and experimental proofs of God's presence, still cried (Exo 17:7), "Is the Lord among us or not?" (Compare Mar 8:11).

except ye be reprobates--The Greek softens the expression, "somewhat reprobates," that is, not abiding the "proof" (alluding to the same word in the context); failing when tested. Image from metals (Jer 6:30; Dan 5:27; Rom 1:28).