Notes & Commentary:
Ver. 1. To write. From hence it would appear, says Grotius, that St. Paul had intended to have finished his letter at the end of the preceding chapter; but something new occurring to him, he added the two following chapters.
Ver. 2. Beware of dogs. The Jews called so the Gentiles; and St. Paul now applies it to those among the Jews who spread false doctrine, who privately snarled and publicly barked against the true apostles. None deserve sharp reprehension more than heretical preachers. — Beware of the concision, or as some French translations, of false circumcision. St. Paul by derision makes use of this word, which signifies a cutting to pieces, or destruction. (Witham)
Ver. 3. For we are the circumcision. We Christians now use the only profitable and commendable spiritual circumcision; which, to the Colossians (ii. 11.) he calls the circumcision of Christ, and to the Romans (ii. 29.) circumcision of the heart in the spirit. — Not having confidence in the flesh; i.e. in such carnal ceremonies. (Witham)
Ver. 4-7. If any other thinketh he may have confidence in the flesh, in being of the Jewish race and of their religion, I more; i.e. I have greater reasons to glory than they have, being circumcised of the stock of Israel, &c. — But what things, &c. as soon as I was miraculously called to the knowledge and faith of Christ. (Witham)
Ver. 9. I may be found in him not having my justice, which is of the law; i.e. not pretending to be justified either by my own works or by the works of the Jewish law, but by that which proceedeth from faith in Christ, and by his merits. (Witham) — St. Augustine expounds the sense thus: not that justice which is in God, or by which God is just, but that which is in man from God, and by his gifts. (lib. 3. cont. 2. ep. Pelag.)
Ver. 10. That I may know him. This knowledge of Christ the apostle prefers to all honours and advantages accruing from his adherence to the synagogue.
Ver. 11. If by any means I may attain to the resurrection, which is from the dead; i.e. may attain to a happy resurrection, when the dead shall rise again. (Witham) — This manner of expression does not betray any distrust or fear, but merely insinuates the difficulty of the enterprise, the uncertainty of success, and the ardent desire of the apostle, who sought by every means to arrive at this happiness, either by sufferings and labours, or even by martyrdom. (St. Chrysostom; Estius)
Ver. 12. Not as though I had already attained the happiness I hope for, or am now become perfect as to that perfection in virtue, which I must always endeavour to increase in; but, like a person still running a race for a prize, I pursue and run as well as I can, I stretch myself with perseverance towards the mark, forgetting that part of the course which I had made. Let all of us, though perfect as to the knowledge of the mysteries we are to believe, be of this mind, that we are still to advance in the way of Christian perfection; and if any of you be of another mind, and think otherwise, God will reveal to you and teach you this truth, that we may all continue in the same rule of doctrine and discipline. We may here take notice with St. Chrysostom that it is not enough to believe, or have the true faith, but that we must strive and labour to the end in the way of perfection; secondly that St. Paul did not look upon himself absolutely certain of his salvation: and how much greater presumption would this be in us? (Witham)
Ver. 13. I do not count myself. That is, I do not suppose that vain security is sufficient to put my salvation out of doubt, and that Christ having died, nothing remains for me to do. No; I consider myself as a wrestler at the games, uncertain of success. (Calmet)
Ver.17. Be followers of me, always in distrust of your own merits, and always eager to advance in perfection, as I am. It is a happy thing when a pastor can thus in all sincerity and simplicity address his flock. — He exhorts them to follow him in what he had taught them, and in the model of a good life, which he had set before them. He repeats to them, with tears, what he had formerly told them, that many walk and conduct themselves as enemies to the cross of Christ, to Christ crucified, by abandoning themselves to the pleasures of a sensual life, who glory in things they ought to be ashamed of. He hints at the disciples of Simon Magus, or of the Jewish doctors. (Witham)
 Ver. 2. Videte canes….Videte Concisionem, blepete tous kunas….ton katatomen. The Jewish circumcision at this time, says St. Chrysostom (log. 1.) was merely a cutting off of the flesh: ouden allo e sarkos tome esti, kai katatome.
 Ver. 14. Ad destinatum, kata skopon dioko. See St. Chrysostom of the necessity of good works, (log. is. p. 65) and of the uncertainty a man is always in of his salvation. p. 67.
Bible Text & Cross-references:
He warneth them against false teachers: he counts all other things loss, that he may gain Christ.
1 As to the rest, my brethren, rejoice in the Lord. To write the same things to you, to me indeed is not wearisome, but to you necessary.
2 Beware of dogs, beware of evil workers, beware of the concision.
3 For we are the circumcision, who serve God in spirit, and glory in Christ Jesus, not having confidence in the flesh:
4 Though I might also have confidence in the flesh. If any other thinketh he may have confidence in the flesh, I more,
5 Being circumcised the eighth day, of the stock of Israel, of the tribe of Benjamin, a Hebrew of the Hebrews, *as to the law a Pharisee,
6 As to zeal, persecuting the church of God, as to the justice that is in the law, conversing without blame.
7 But what things were gain to me, those I have counted loss for Christ.
8 But indeed I count all things to be but loss, for the excellent knowledge of Jesus Christ, my Lord: for whom I have suffered the loss of all things, and count them but as dung, that I may gain Christ,
9 And may be found in him not having my justice, which is of the law, but that which is of the faith of Christ Jesus: the justice which is of God in faith,
10 That I may know him, and the power of his resurrection, and the fellowship of his sufferings, being made conformable to his death:
11 If by any means I may attain to the resurrection, which is from the dead:
12 Not as though I had already attained, or were already perfect: but I follow after, if I may by any means apprehend that in which I am also apprehended by Christ Jesus.
13 Brethren, I do not count myself to have apprehended. But one thing I do: forgetting the things that are behind, and stretching forth myself to those that are before,
14 I pursue towards the mark, for the prize of the supernal vocation, of God in Christ Jesus.
15 Let us, therefore, as many as are perfect, be thus minded: and if in any thing you be otherwise minded, this also God will reveal to you.
16 Nevertheless whereunto we are already come, that we be of the same mind: let us also continue in the same rule.
17 Be followers of me, brethren, and observe them who walk so, as you have our model.
18 *For many walk, of whom I have told you often (and now tell you weeping) that they are enemies of the cross of Christ:
19 Whose end is destruction: whose God is their belly: and whose glory is in their shame, who mind earthly things.
20 But our conversation is in heaven: whence also we expect the Saviour, our Lord Jesus Christ,
21 Who will reform the body of our lowness, made like to the body of his glory, according to the operation whereby also he is able to subdue all things unto himself.
5: Acts xxiii. 6.
18: Romans xvi. 17.