Don't make me drag out all the quotes from Trent.
Do it, please!
the instrumental cause is the sacrament of baptism, which is the sacrament of faith, without which (faith) no man was ever justified;
In Baptism is bestowed the supernatural faith, whereby a man is justified. This is
de fide.
For, although no one can be just, but he to whom the merits of the Passion of our Lord Jesus Christ are communicated, yet is this done in the said justification of the impious, when by the merit of that same most holy Passion, the charity of God is poured forth, by the Holy Spirit, in the hearts of those that are justified, and is inherent therein: whence, man, through Jesus Christ, in whom he is ingrafted, receives, in the said justification, together with the remission of sins, all these (gifts) infused at once, faith, hope, and charity.
These are all received at once at Baptism.
For faith, unless hope and charity be added thereto, neither unites man perfectly with Christ, nor makes him a living member of His body. For which reason it is most truly said, that Faith without works is dead and profitless; and, In Christ Jesus neither circuмcision, availeth anything, nor uncircuмcision, but faith which worketh by charity. This faith, catechumens beg of the Church-agreeably to a tradition of the apostles-previously to the sacrament of Baptism; when they beg for the faith which bestows life everlasting, which, without hope and charity, faith cannot bestow:
The tradition of the Apostles is that this saving faith does not exist in a catechumen previously to Baptism.
Finally, Trent teaches that no man can be justified (as you know) without the laver of regeneration or the
votum for it. These are not mutually exclusive
causes of justification, but both are required for justification to take place.
There is not dogmatic support for the contrary heretical opinion ANYWHERE.