2 Cor. 13:9. We pray about this very thing — about your perfection.
The meaning of his words is as follows: I not only desire this, but also pray that you may be blameless and innocent, that is, perfect, giving no occasion for punishment.
2 Cor. 13:10. For this reason I write these things being absent, so that being present I should not use sharpness, according to the authority which the Lord has given me for edification, and not for destruction.
Having greatly frightened them and put forth threats, he now presents a justification for this. I wrote thus because I desire that the threats and severity remain only in writing and not be carried out in reality; for I will certainly punish those who have not corrected themselves, since the Lord gave me authority. By this he shows that through him the Lord Himself punishes. And showing that he does not wish to use his authority for their punishment, he adds: "for building up, and not for tearing down," that is, the Lord does not wish to tear down, or punish, but to build up, that is, to do good. Nevertheless, to punish the incorrigible is itself building up.
2 Cor. 13:11. Finally, brethren, rejoice,
I, he says, have done my part; it remains for you to act in accordance with me. For if you correct your life, you will gain unfading joy in your conscience, even though I grieved you with my words.
2 Cor. 13:11. Be perfected,
That is, be perfect both in teaching and in life, and supply that which is lacking in you.
2 Cor. 13:11. Be comforted,
Since there were many temptations and dangers, he says to them: seek consolation in yourselves, in one another, and in your own change for the better; for a good conscience is a great consolation.
2 Cor. 13:11. Be of one mind, be at peace.
He was asking them about this, as people who were in disagreement, in his first epistle as well (1 Cor. 1:10). Being of one mind relates to dogmas, while being at peace ("be at peace") — a concept opposite to discord — refers to people's relations with one another. Therefore Paul demands both.
2 Cor. 13:11. And the God of love and peace will be with you.
He not only exhorts them but also prays for them. Or else these words contain not a prayer but a prediction that if you mutually preserve peace, then God will be with you. God is called the God of love either because He is its source, or because He abundantly manifests it in us, or because where there is love, there He is and is its Lord. Likewise, He is called the God of peace either because He is its source, or because He reconciled the heavenly with the earthly, or because He is its Lord, as of His own possession.
2 Cor. 13:12. Greet one another with a holy kiss.
Not with a pretended and treacherous kiss, like that of Judas. For we kiss one another for the purpose of kindling love all the more, since through the mouth, more than through any other member, the souls of those who kiss are united. Likewise, when entering a house, we express our unity through a kiss. Or else, since we are the temple of God, and the mouth is the entrance to this temple, we kiss this entrance, for through it Christ enters into us during communion.
2 Cor. 13:12. All the saints greet you.
The present he unites with a kiss, the absent with a greeting, but even here the lips are joined, because the greeting proceeds from them.
2 Cor. 13:13. The grace of our Lord Jesus Christ, and the love of God the Father, and the communion of the Holy Spirit be with you all. Amen.
Having united all together, he, according to his custom, prays that the grace of the Son be upon them, through which He saved us — not by our works, but by grace, having Himself endured being slain for us. And then, as if being asked — whence comes this grace of the Son? he answers: from the love of the Father. And what does it produce? The communion of the Holy Spirit, that is, participation and partaking of Him, by virtue of which we are sanctified — having become, through the indwelling of the Comforter in us, partakers of Him, we ourselves also become spirit, not by nature, but through communion. What ground, then, do those have who reject the Spirit on the basis that Paul did not mention Him at the beginning of the epistles? Here he mentions and fully enumerates the Trinity, which may preserve us holding firmly to the dogmas and leading a blameless life, so that we may be perfect servants of the perfect God in Trinity, to Whom be glory unto the ages of ages. Amen.