Pope Paul III, Council of Trent, Decree on Justification, Chapter VII: "The causes of justification are: ... the instrumental cause, the sacrament of baptism, which is the sacrament of faith, without which justification comes to no one. ... From apostolic tradition, catechumens seek this faith from the church before the sacrament of baptism when they ask the faith that gives eternal life ..."
First of all, it says quite clearly that THE INSTRUMENTAL CAUSE is the SACRAMENT, yet some heretics have said that this decree actually refers to faith as the thing that no one is ever justified without, not baptism. First of all, I agree that nobody with the use of reason is ever justified without faith. This is true. But I also assert that nobody is ever justified without baptism, since the decree clearly says THE SACRAMENT OF BAPTISM is the instrumental cause, and IT is what bestows the FAITH that gives eternal life.
Now, the heretics also like to argue that, according to the following decree, we can be justified by faith (the desire of the sacrament, the faith of the sacrament, etc.) without actually receiving the sacrament.
Pope Paul III, Council of Trent, Decree on Justification, Chapter IV: "This translation to the state of justification however cannot be effected without the laver of regeneration or its desire"
If they are to hold this position, that the decree is teaching that you can be justified WITH ONLY ONE BUT NOT THE OTHER, then they also have to say that justification can occur by receiving the sacrament, yet not having the desire for it. And before people start making the silly argument that "Babies can't desire the sacrament, etc." They need to realize the context of the decree:
Pope Paul III, Council of Trent, Decree on Justification, Chapter IV, A description is introduced of the Justification of the impious, and of the Manner thereof under the law of grace."
Impiety is a willful state of being, so this decree is speaking of those with the use of reason, who are able to desire the sacrament.