CANON I.-If any one saith, that man may be justified before God by his own works, whether done through the teaching of human nature, or that of the law, without the grace of God through Jesus Christ; let him be anathema.This canon correctly rejects salvation by works alone without grace. Its unnecessary qualification of "without the grace of God" is part of the reason we would not use this formulation ourselves, but in itself it is not wrong.
CANON II.-If any one saith, that the grace of God, through Jesus Christ, is given only for this, that man may be able more easily to live justly, and to merit eternal life, as if, by free will without grace, he were able to do both, though hardly indeed and with difficulty; let him be anathema.The thrust of this canon is similar to that of canon 1. This one emphasizes that grace doesn't simply make it easier for a man to justify himself through works. Again, we would tend not to formulate things this way, because we would deny that man's works have any role in justification. Nevertheless, this canon is not wrong in itself.
CANON III.-If any one saith, that without the prevenient inspiration of the Holy Ghost, and without his help, man can believe, hope, love, or be penitent as he ought, so as that the grace of Justification may be bestowed upon him; let him be anathema.This canon rightly rejects the idea that without God's aid man can believe, hope, love, or be penitent as he ought or obtain justification. We would never word the canon this way, because it suggests that man obtains justification on account of works that are simply encouraged by prevenient grace. Nevertheless, in itself this canon is not wrong.
CANON VI.-If any one saith, that it is not in man's power to make his ways evil, but that the works that are evil God worketh as well as those that are good, not permissively only, but properly, and of Himself, in such wise that the treason of Judas is no less His own proper work than the vocation of Paul; let him be anathema.As with a number of the canons of Trent, this one seems to be aimed in the general direction of the Reformed churches, but does not actually direct itself to what the Reformed churches teach. As such, what it condemns is error, and it s right to condemn it. It condemns the idea that God is directly active in sin or that man is inactive in sin.
CANON X.-If any one saith, that men are just without the justice of Christ, whereby He merited for us to be justified; or that it is by that justice itself that they are formally just; let him be anathema.This one is only half right. The first half that affirms the necessity of the justice (righteousness) of Christ for justification. That part is correct, while the second part is not (we will deal with that in another post).
CANON XIII.-If any one saith, that it is necessary for every one, for the obtaining the remission of sins, that he believe for certain, and without any wavering arising from his own infirmity and disposition, that his sins are forgiven him; let him be anathema.This is another one of those canons that appears to be aimed at the Reformed churches, but which misses. There is no requirement that one be absolutely free from wavering, although (of course) such wavering bad.
CANON XIV.-If any one saith, that man is truly absolved from his sins and justified, because that he assuredly believed himself absolved and justified; or, that no one is truly justified but he who believes himself justified; and that, by this faith alone, absolution and justification are effected; let him be anathema.This is another one of those canons that appears to be aimed at the Reformed churches, but which misses. Justification is by faith in Christ, not in justification by faith in justification.
CANON XV.-If any one saith, that a man, who is born again and justified, is bound of faith to believe that he is assuredly in the number of the predestinate; let him be anathema.This is another one of those canons that appears to be aimed at the Reformed churches, but which misses. The key phrase here is that phrase "bound of faith" which describes the matter as being a necessary thing to be believed. Those who are born again and justiifed should be assured of their place among the predestinate. Nevertheless, that is not an essential doctrine.
CANON XIX.-If any one saith, that nothing besides faith is commanded in the Gospel; that other things are indifferent, neither commanded nor prohibited, but free; or, that the ten commandments nowise appertain to Christians; let him be anathema.This canon properly condemns antinomianism.
CANON XX.-If any one saith, that the man who is justified and how perfect soever, is not bound to observe the commandments of God and of the Church, but only to believe; as if indeed the Gospel were a bare and absolute promise of eternal life, without the condition of observing the commandments ; let him be anathema.Aside from the explanation "as if indeed the Gospel were a bare and absolute promise of eternal life, without the condition of observing the commandments," this canon simply similarly condemns antinomianism. That additional explanation suggests that Trent mistakenly viewed the Reformed position as antinomianism by mistakenly creating a dichotomy between the Gospel promise being absolute and unconditioned on works, and antinomianism. The Reformed position lies in the middle. The error of conditioning the Gospel on works will be addressed in another post.
CANON XXI.-If any one saith, that Christ Jesus was given of God to men, as a redeemer in whom to trust, and not also as a legislator whom to obey; let him be anathema.Again, this is a proper condemnation of antinomianism.
CANON XXII.-If any one saith, that the justified, either is able to persevere, without the special help of God, in the justice received; or that, with that help, he is not able; let him be anathema.This canon properly condemns the ideas either that perseverance is possible without God's aid or impossible with God's aid.
So, as you can see, just because Trent said it doesn't make it bad. I'm following a rather abbreviated format here, because I'm agreeing with Trent on these issues (with various qualifications). Nevertheless, we do not simply use an ad hominem standard that because Trent was a bad council, therefore everything it says was wrong. No, Trent sometimes anathematized errors, such as the errors of Pelagianism (denying the necessity of grace) and Antinomianism (denying any continued value to the law).