Since ye seek a proof of Christ speaking in me, which to you-ward is not weak, but is mighty in you.
For though he was crucified through weakness, yet he liveth by the
power of God. For we also are weak in him, but we shall live with him by
the power of God toward you. Examine yourselves, whether
ye be in the faith; prove your own selves. Know ye not your own selves,
how that Jesus Christ is in you, except ye be reprobates? But I trust that ye shall know that we are not reprobates.
Now I pray to God that ye do no evil; not that we should appear
approved, but that ye should do that which is honest, though we be as
reprobates. For we can do nothing against the truth, but for the truth. For we are glad, when we are weak, and ye are strong: and this also we wish, even your perfection.
Therefore I write these things being absent, lest being present I
should use sharpness, according to the power which the Lord hath given
me to edification, and not to destruction. Finally,
brethren, farewell. Be perfect, be of good comfort, be of one mind, live
in peace; and the God of love and peace shall be with you. Greet one another with an holy kiss. All the saints salute you.
St. John Chrysostom said in his Homilies XXIX, 3,4 and XXX, 2 on II Corinthians XIII:
"Let not then the expression 'weakness' disturb you, for elsewhere he also says, 'the foolishness of God is wiser than men, and the weakness of God is stronger than men' (I Cor.1:25) although in God there is nothing either foolish or weak, nevertheless he called the Cross so, as setting forth the conception of the unbelieving regarding it…Even though He was crucified after enduring peril and treachery…still He was not at all harmed thereby. And he said this to draw an example of his own case. The Corinthians saw them persecuted, driven about, despised, and not avenging nor visiting it, so in order to teach them that they do not suffer in this way from want of power, nor from being unable to visit it, he leads the argument up to the Master…When you hear of the Cross and of life, expect to find the doctrine concerning the Incarnation, for all that is said here has reference to that…He has shown that even if he does not punish, it is not because he does not have Christ in himself, but because he intimates His long-suffering, Who was crucified and yet did not avenge Himself…"
"We are the temple of Christ; we kiss the porch and entrance of the temple when we kiss each other…And through these gates and doors Christ both has entered into us and does enter, whensoever we communicate. You who partake of the mysteries understand what I say. For it is in no common manner that our lips are honored when they receive the Lord's Body. It is chiefly for this reason that we kiss. Let those give ear who speak filthy things, who utter railing, and let them shudder to think what that mouth is they dishonor…Hear what things God has proclaimed by your mouth, and keep it undefiled. He has discoursed of the life to come, of the resurrection, of immortality, that death is not death, and of those other innumerable mysteries."
In the book Way of Silent Love by A. Carthusian, I found an interesting thought on the word 'peace' as found in v.11:
"…God is not a God of disorder but of peace' (I Cor.14:33), and 'it is to peace that God has called you' (I Cor.7:15). 'Agree with one another, live in peace; and the God of love and peace will be with you' (II Cor.13:11), we are promised by the word of God. Let us therefore be the peacemakers of which the beatitude speaks."
"The meaning of the Greek word (eirenopoios) that is translated 'peacemaker' or 'who does the work of peace' is difficult to determine because it is not found elsewhere in the Bible. Palestinian revisions render it, 'Those who establish peace' or 'those who pursue peace'. In the rabbinic sense, to pursue peace is to try to obtain it to incorporate it in oneself, so that its rule prevails around one. It does not, therefore, necessarily insist on the role of peacemaker, that is to say, someone burdened with reconciling enemies (P. Buzy, commentary on St.Matthew)
St. Seraphim of Sarov:
"Find peace, and thousands around you will find it also.
St. Mark the Ascetic in 1, On the Spiritual Law, Sec.192 wrote:
"Peace is deliverance from the passions, and is not found except through the action of the Holy Spirit."
St. Maximos the Confessor (6-7th C.) in the Philokalia vol.II said:
"He who through practice of the virtues has succeeded in mortifying whatever is earthly in him (Col.3:5), and who by fulfilling the commandments has triumphed over the world of the passions within him, will experience no more affliction; for he will have already left the world and come to be in Christ, the conqueror of the world of the passions and the source of all peace. He who has not severed his attachment to material things will always experience affliction, since his state of mind depends on things that are naturally changeable, and so it alters when they do. But he who has come to be in Christ will be totally impervious to such material change. That is why the Lord says, 'I have said these things to you, so that in Me you may have peace. In the world you will experience affliction; but have courage, for I have overcome the world' (Jn.16:33). In other words, 'In Me, the Logos of virtue, you have peace, for you have been released from the swirl and turmoil of material passions and objects; in the world – that is, in a state of attachment to material things – you are afflicted because of the successive changes of these things.' For both he who practices the virtues and he who loves the world experience affliction, the first because of the toil which such practice entails and the second because of the futility of material things. But the affliction of the first is salutary, that of the second corrupting and destructive. The Lord gives release to both: in the case of the first He allays the toil of ascetic practice with the contemplation attained through dispassion, and in the case of the second He rescinds attachment to corrupted things by means of repentance."