Trent teaches that justification happens as a COOPERATION between grace and free will (i.e. works) This declaration says that justification happens by "grace alone", which then predisposes or "calls" us towards "good works". No, even in the act of justification, the will must cooperate with the grace in order to make it happen. This has us being passively "accepted by God" through "grace alone". It's Protestantism in a nutshell and a total capitulation by the Roman Modernists.
All our good works come from God's grace. Without God's grace we could not perform any good works. All our good thoughts come from God's grace. When we die, we will know what little we actually did to save ourselves,
it may be as little as inclining ourselves 0.0010% toward God and He did the rest (by giving us the Grace), HOWEVER, we did do something to save ourselves. We were not just robots.
The Lutherans take what I just wrote, and say that we do NOTHING of our own, that it ALL comes from God's Grace. That heresy is akin to the Arian Heresy, where they said that Christ was God, however, that He was 1/10 of one hair away from the Father.