Gaebelein's Annotated Bible
This is the third time I am coming to you. In the mouth of two or three witnesses shall every word be established.4. Still Absent - Yet Coming. The Conclusion.
He speaks in conclusion of his coming to them. “This third time I am coming to you.” And when he comes again he will not spare them. He reminds them once more of their doubtings about Christ speaking in him and using him as an apostle. They themselves were proof of this. If it were that Christ had not spoken to them through him (by preaching the Gospel), then Christ also did not dwell in them. But if Christ really was in them then it was an evidence that Christ had spoken by him. Notice that part of the third verse and the fourth verse are parenthetical. Leaving out the parenthetical words gives us the correct argument. “Since ye seek a proof of Christ speaking in me--examine yourselves, whether ye be in the faith, prove your ownselves. Do ye not know yourselves that Jesus Christ is in you, except ye be reprobates?” What he wished was their perfecting. Why had he written this second epistle? “I write these things being absent, but being present I should use sharpness, according to the power which the Lord hath given me to edification, and not to destruction.”
“Finally, brethren, rejoice.” (Not farewell, but rejoice.) And the believers joy as well as glorying is in the Lord. “Be perfected; be of good comfort; be of one mind; be at peace; and the God of love and peace shall be with you.”