But God forbid that I should glory, save in the Cross of our Lord Jesus Christ.

Beautiful on the Cross from St. Thomas Aquinas, commentary on Galatians 6: 14-15, Dominican House of Studies, Priory of the Immaculate Conception website, translated by F.R. Larcher, O.P. 

CHAPTER 6
Lecture 4  

14 But God forbid that I should glory, save in the cross of our Lord Jesus Christ; by whom the world is crucified to me, and I to the world. 15 For in Christ Jesus neither circumcision availeth any thing, nor uncircumcision; but a new creature.

After unmasking the sinister intention of the seducers, the Apostle here insinuates his own intention. First, he states his intention; Secondly, he gives a sign of this intention (v. 14); Thirdly, the reason for this intention (v. 15).

He says therefore: The intention of the seducers is obvious, for they glory in the flesh; but I seek my glory elsewhere, namely, in the Cross. And this is what he says: But God forbid that I should glory, save in the cross of our Lord Jesus Christ. Notice that where the worldly philosopher felt shame, there the Apostle found his treasure: what the former regarded as foolish became for the Apostle wisdom and glory, as Augustine says. For each person glories in that through which he is considered great. Thus a person who regards himself as great in his riches, glories in them; and so on for other things. For one who regards himself to be great in nothing but Christ glories in Christ alone. But the Apostle was such a one; hence he says: I live now not I; but Christ liveth in me (2:20).

 

Accordingly he glories in nothing but Christ and particularly in the Cross of Christ; and this because in it are found all the things about which men usually glory. For some glory in the friendship of the great, such as of kings and princes; and this friendship the Apostle found most of all in the Cross, because there an obvious sign of divine friendship is shown: “But God commendeth his charity towards us; because when as yet we were sinners according to the time, Christ died for us” (Rom 5:8). For nothing shows His mercy to us as much as the death of Christ. Hence Gregory: “O inestimable love of charity! To redeem the servant, He delivered His Son.”
 

Again, some glory in knowledge; and of this the Apostle found a more excellent one in the cross: “For I judged not myself to know anything among you but Jesus Christ and him crucified” (1 Cor 2:2). For in the Cross is the perfection of all law and the whole art of living well. Again, some glory in power; and of this the Apostle found the highest form through the Cross: “The word of the cross to them, indeed, that perish is foolishness; but to them that are saved, that is, to us, it is the power of God” (1 Cor 1:18). Again, some glory in newly-found freedom; and this the Apostle obtained through the Cross: “Our old man is crucified with him that the body of sin may be destroyed, to the end that we may serve sin no longer” (Rom 6:6).
 

Again, some glory in being accepted into some famous fellowship; but by the Cross of Christ, we are accepted into the heavenly ranks: “Making peace through the blood of his cross, both as to the things that are on earth and the things that are in heaven” (Col 1:20). Again, some glory in the triumphal banners of conquest; but the Cross is the triumphal ensign of Christ’s conquest over the demons: “And despoiling the principalities and powers, he hath exposed them confidently in open show, triumphing over them in himself” (Col 2:15); “Blessed is the wood by which justice cometh” (Wis 14:7).
 

The sign of his own intention he shows, saying by whom the world is crucified to me, and I to the world. But since this which he says, But God forbid that I should glory save in the cross of our Lord Jesus Christ, is an exceptive proposition which includes one affirmative and one negative statement, he is really giving two signs that prove both statements. First, he proves the negative one, namely, that he does not glory save in the cross. He does this when he says, by whom the world is crucified to me, and I to the world. For that in which a person glories is not dead in his heart, but rather that which he scorns: I am forgotten as one dead, from the heart” (Ps 30:13). But it is plain that the world and all things in it were dead in the heart of Paul: “I count all things as dung, that I may gain Christ” (Phil 3:8). Therefore he does not glory in the world or in the things that are in the world. And this is what he says: Verily, I glory in nothing save in the cross of Christ, by whom, namely, Christ crucified, the world is crucified to me, i.e., is dead in my heart, so that I covet nothing in it.

 

Secondly, he proves the affirmative, namely, that he glories in the Cross of Christ, saying that he is crucified to the World. For a person who glories in something treasures it and desires to make it known; but the Apostle treasures nothing or desires to make nothing known except what pertains to the Cross of Christ; therefore, he glories in it alone. And this is what he says: and I to the world, namely, I am crucified. As if to say: I carry the marks of the Cross and I am considered as dead. Therefore, as the world abhors the Cross of Christ, so it abhors me: “For you are dead and your life is hid with Christ in God” (Col 3:3).
 

The reason why he glories in nothing else is given when he says, For in Christ Jesus neither circumcision availeth any thing nor uncircumcision, but a new creature. Indeed, he glories mainly in that which avails and helps in joining him to Christ; for it is this the Apostle desires, namely, to be with Christ. And because the Jewish rite and the observances of the Gentiles are of no avail in this regard, but only the Cross of Christ, therefore he glories in it alone. And this is what he says: For in Christ Jesus neither circumcision, i.e., the Jewish rite, nor uncircumcision, i.e., Gentile observances, availeth any thing, i.e., to justify us and join us to Christ, but a new creature availeth for us. This, indeed, is obvious from what was said above, in almost the same words: For in Christ Jesus neither circumcision availeth anything nor uncircumcision; but faith that worketh by charity (5:6). Therefore, faith informed by charity is the new creature. For we have been created and made to exist in our nature through Adam, but that creature is already old. Therefore, the Lord in producing us and establishing us in the existence of grace has made a new creature: “That we might be some beginning of his creature” (Jam 1:18). And it is called “new,” because by it we are reborn into a new life by the Holy Spirit”—Thou shalt send forth thy spirit and they shall be created: and thou shalt renew the face I the earth” (Ps 103:30)—and by the Cross of Christ: “If then any be in Christ a new creature, the old things are passed away, behold all things are made new” (2 Cor 5:17). In this way, then, by a new creature, i.e., by the faith of Christ and the charity of God which has been poured out in our hearts, we are made new and are joined to Christ.