Fratres: Gaudete in Domino semper: iterum dico, gaudete. Modestia vestra nota sit omnibus hominibus: Dominus prope est. Nihil soliciti sitis: sed in omni oratione, et obsecratione, cum gratiarum actione, petitiones vestrae innotescant apud Deum. Et pax Dei, quæ exsuperat omnem sensum, custodiat corda vestra et intelligentias vestras, in Christo Iesu Domino nostro. (Epistle for the Third Sunday in Advent, Philippians iv, 4-7: Brethren, Rejoice in the Lord always: again I say, rejoice. Let your modesty be known to all men. The Lord is nigh. Be nothing solicitous: but in every thing, by prayer and supplication, with thanksgiving, let your petitions be made known to God. And the peace of God, which surpasseth all understanding, keep your hearts and minds in Christ Jesus our Lord.)
"Blessed they that mourn," and "woe unto them that laugh" (Matt. v. 4; Luke vi. 25), says Christ. How then does Paul say, "Rejoice in the Lord always"? "Woe to them that laugh," said Christ, the laughter of this world which arises from the things which are present. He blessed also those that mourn, not simply for the loss of relatives, but those who are pricked at heart, who mourn their own faults, and take count of their own sins, or even those of others.
This joy is not contrary to that grief, but from that grief it too is born. For he who grieves for his own faults, and confesses them, rejoices. Moreover, it is possible to grieve for our own sins, and yet to rejoice in Christ. Since then they were afflicted by their sufferings, "for to you it is given not only to believe in him, but also to suffer for him" (Phil. i. 29), therefore he says, "Rejoice in the Lord", for this can but mean: if you exhibit such a life that you may rejoice. ... If scourging and bonds, which seem to be the most grievous of all things, bring forth joy, what else will be able to produce grief in us?
"Again I say, Rejoice." Well has he repeated. For since the nature of the things brought forth grief, he shows by repeating, that they should by all means rejoice.
..."Be nothing solicitous." The judgment is already at hand, when these things shall be reversed. "Be nothing solicitous": if you are kindly affected toward those who prepare evil against you, yet it shall not at last turn out to their profit. Already the reward is at hand, if poverty, if death, if aught else that is terrible be upon you. "but in every thing, by prayer and supplication, with thanksgiving, let your petitions be made known to God." There is this for one consolation, "the Lord is nigh."...
"And the peace of God, which surpasseth all understanding, keep your hearts and minds in Christ Jesus." What does this mean? "The peace of God" which He has wrought toward men, surpasses all understanding. For who could have expected, who could have hoped, that such good things would have come? They exceed all man's understanding, not his speech alone. For His enemies, for those who hated Him, for those who determined to turn themselves away, for these, he refused not to deliver up His Only Begotten Son, that He might make peace with us.
Saint John Chrysostom