Justification comes first from baptism but can then be lost by committing mortal sins. Justification can then be regained by confession, reconciliation and penance, which involves confessing sins and doing good works to make up for them.
Purgatory
A place Catholics believed existed for Christians who hadn't done enough penance for their sins before dying
Indulgences
Certificates authorized by the pope granting a sinner freedom from penance, sold for money
Epistle of James
Suggests justification is by works, not faith alone
James: 'Faith without works is dead'
Parable of the Sheep and the Goats
Suggests works are important for justification/salvation
Justification by faith
Salvation comes to "everyone who has faith", not through good works
Sola fide
Justification by faith alone
Luther rejected the Epistle of James as 'straw' and even tried to get it removed from the Bible
Council of Trent's response to Luther
Both faith and works are required for justification because works are an essential part of faith
The council claimed that faith alone "neither unites man perfectly with Christ nor makes him a living member of His body
The council was very clear, in direct opposition to Luther, that good works are not "merely the fruits and signs of justification" but are part of the "cause" and "preservation" of justification
Protestants
Claim Trent's proclamation contradicts the bible teaching that good works do not merit grace because grace is a "gift" from God
Catholic view of justification
1. Righteousness is enabled through baptism. 2. Righteousness is preserved and regained (if lost) by participation in the Eucharist and by penance which includes doing good works.
Neither faith nor works can be said to merit justification, but both count as progress towards it, which humans can make as their part in a cooperation with God wherein they can ultimately be justified
E.P. Sanders' critique of Luther's interpretation of Paul
Paul was actually remarking on the shift in the nature of God's covenant from the Jewish to the Christian version, not discounting justification by works
Sanders points out that "Paul loved good deeds" and recommends them "all the time"
Protestants
Claim there is plenty of other biblical evidence for Sola Fide
Some Catholics respond that in the historical context of ancient Judaism, the word "believe" meant more than a mere intellectual assent, it also meant to obey