I am glad of the coming of Stephanas and Fortunatus and Achaicus: for that which was lacking on your part they have supplied.

And I rejoice in the presence of Stephanas, and Fortunatus, and Achaicus, because that which was wanting on your part, they have supplied.

But I rejoice in the coming of Stephanas and Fortunatus and Achaicus; because they have supplied what was lacking on your part.

and I rejoice over the presence of Stephanas, and Fortunatus, and Achaicus, because the lack of you did these fill up;

It is a joy to me that Stephanas, Fortunatus and Achaicus have now arrived, because what was wanting so far as you are concerned they have supplied.

And I am glad of the coming of Stephanas and Fortunatus and Achaicus: for they have done what was needed to make your work complete.

Now I rejoice in the presence of Stephanus and Fortunatus and Achaicus, because what was lacking in you, they have supplied.

I am glad Stephanas and Fortunatus and Achaicus have come, for they have made up for your absence;

I am glad of the coming - That is, I am glad that they have come to me at Ephesus. I rejoice that he who was converted by my ministry in Achaia, and who has so long shown himself to be a personal friend to me, and an aid in my work, came where I am.
Stephanas - The same person evidently mentioned in the previous verses. Probably he, as one of the oldest and most respected members of the church, had been selected to carry the letter of the Corinthians 1-Corinthians 7:1 to Paul, and to consult with him respecting the affairs of the church there.
Fortunatus and Achaieus - These persons are not referred to anywhere else in the New Testament. It appears that Fortunatus survived Paul, for he was subsequently the messenger of the church at Corinth to that at Rome, and bore back to the Corinthians the Epistle which Clement of Rome sent to them. See that epistle, Section 59.
For that which was lacking - The word which is used here, and rendered "that which was lacking" (ὑστέρημα husterēma), does not occur in the Classic writers. It means properly that which is missing, want, lack - Robinson. It may be used to denote a want or lack of any kind, whether of support, sustenance, aid, consolation, information, or counsel; see Luke 21:4; Philippians 2:30; 1-Thessalonians 3:10. What this was which the Corinthians had neglected or failed to furnish Paul, and which had been supplied by the presence of these persons, can be only a matter of conjecture; and different commentators have supposed different things. It might be a neglect to provide for his needs, or a defect of informing him about their affairs in the letter which they had sent him; or it might be that these persons had furnished, by their presence and conversation, those consolations and friendly offices which the church at Corinth would have rendered had they been all present; and Paul may mean to say, that he had enjoyed with them that friendly contact and Christian communion which he had desired with them, but which was lacking, that is, which he had not been permitted to enjoy by reason of his absence. This is the view which is given by Rosenmuller, Doddridge, Bloomfield; and as Paul does not seem here inclined to blame them, this view is most in accordance with the general strain of the passage.

I am glad of the coming of Stephanas, etc. - It was by these that the Corinthians had sent that letter to the apostle, to answer which was a main part of the design of St. Paul in this epistle.
Fortunatus - This man is supposed to have survived St. Paul; and to be the same mentioned by Clement in his epistle to the Corinthians, sec. 59, as the bearer of that epistle from Clement at Rome to the Christians at Corinth.
For that which was lacking on your part - This may either refer to additional communications besides those contained in the letter which the Corinthians sent to the apostle - which additional circumstances were furnished by the persons above; and from them St. Paul had a fuller account of their spiritual state than was contained in the letter - or to some contributions on their part for the support of the apostle in his peregrinations and labors.

I am glad of the coming of Stephanas, and Fortunatus, and Achaicus,.... Who very probably were those of the household of Chloe, mentioned in 1-Corinthians 1:11, who came either of their own accord, or were sent as messengers from the church at Corinth to the apostle; who was glad to see them, one of them being baptized by him, and perhaps all of them converted under his ministry: however, they were believers in Christ, if not ministers of the Gospel, which seems very probable.
For that which was lacking on your part they have supplied; which is not to be understood of their supplying him with money, in which the Corinthians had been deficient; for as he had never taken anything of them, he was determined he never would; see 2-Corinthians 11:7; but either of their presence which supplied the want of theirs, the apostle had been for some time greatly desirous of; or whereas they had been greatly wanting in sending him an account of the state of the church, and how things stood with them, these brethren greatly supplied that defect, by giving him a very particular account of their church affairs.

Fortunatus . . . Achaicus--probably of Stephanas' household.
that . . . lacking on your part--So far as you were unable yourselves to "refresh my spirit," in that you are absent from me, "they have supplied" by coming to me from you, and so supplying the means of intercourse between you and me. They seem to have carried this letter back; see the subscription below: hence the exhortations, 1-Corinthians 16:16, 1-Corinthians 16:18, as though they would be at Corinth when the Epistle arrived.

I rejoice at the coming of Stephanas, and Fortunatus, and Achaiacus - Who were now returned to Corinth but the joy which their arrival had occasioned remained still in his heart. They have supplied what was wanting on your part - They have performed the offices of love, which you could not, by reason of your absence.