What follows is a revealing of the contrast between Reformed writings and the Roman Catholic decrees of Trent concerning the gospel.

How Must we be Saved?
Decrees of Trent
(Chapter V)
The Synod furthermore declares, that in adults, the beginning of the said Justification is to be derived from the prevenient grace of God, through Jesus Christ, that is to say, from His vocation, whereby, without any merits existing on their parts, they are called; that so they, who by sins were alienated from God, may be disposed through His quickening and assisting grace, to convert themselves to their own justification, by freely assenting to and co-operating with that said grace: in such sort that, while God touches the heart of man by the illumination of the Holy Ghost, neither is man himself utterly without doing anything while he receives that inspiration, forasmuch as he is also able to reject it; yet is he not able, by his own free will, without the grace of God, to move himself unto justice in His sight.

Heidelberg Catechism
(Q 60) How are you righteous before God?
Only by true faith in Jesus Christ: that is, although my conscience accuses me, that I have grievously sinned against all the commandments of God, and have never kept any of them, and am still prone to all evil; yet God, without any merit of mine, of mere grace, grants and imputes to me the perfect satisfaction, righteousness, and holiness of Christ, as if I had never committed nor had any sins, and had myself accomplished all the obedience which Christ has fulfilled for me; if only I accept such benefit with a believing heart.

Westminster Shorter Catechism
(Q 85): What doth God require of us that we may escape his wrath and curse due to us for sin?
To escape the wrath and curse of God due to us for sin, God requireth of us faith in Jesus Christ, repentance unto life, with the diligent use of all the outward means whereby Christ communicateth to us the benefits of redemption.

What is Faith?
Decrees of Trent
(Canon IX)
If any one saith, that by faith alone the impious is justified; in such wise as to mean, that nothing else is required to co-operate in order to the obtaining the grace of Justification, and that it is not in any way necessary, that he be prepared and disposed by the movement of his own will; let him be anathema.

Heidelberg Catechism
(Q 21): What is true faith?
True faith is not only a sure knowledge whereby I hold for truth all that God has revealed to us in His Word, but also a hearty trust, which the Holy Spirit works in me by the Gospel, that not only others, but to me also, forgiveness of sins, everlasting righteousness, and salvation are freely given by God, merely of grace, only for the sake of Christ’s merits.

Westminster Shorter Catechism
(Q 86): What is faith in Jesus Christ?
Faith in Jesus Christ is a saving grace, whereby we receive and rest upon him alone for salvation, as he is offered to us in the gospel.

What are Justification & Sanctification?

Decrees of Trent
(Chapter X)
Having, therefore, been thus justified, and made the friends and domestics of God, advancing from virtue to virtue, they are renewed, as the Apostle says, day by day; that is, by mortifying the members of their own flesh, and by presenting them as instruments of justice unto sanctification, they, through the observance of the commandments of God and of the Church, faith co-operating with good works, increase in that justice which they have received through the grace of Christ, and are still further justified, as it is written; He that is just, let him be justified still; and again, Be not afraid to be justified even to death; and also, Do you see that by works a man is justified, and not by faith only. And this increase of justification holy Church begs, when she prays, “Give unto us, O Lord, increase of faith, hope, and charity.”

Heidelberg Catechism
(Q 33): What is justification?
Justification is an act of God’s free grace, wherein he pardoneth all our sins, and accepteth us as righteous in his sight, only for the righteousness of Christ imputed to us, and received by faith alone.

Westminster Shorter Catechism
(Q 35): What is sanctification?
Sanctification is the work of God’s free grace, whereby we are renewed in the whole man after the image of God, and are enabled more and more to die unto sin, and live unto righteousness.