I believe that salvation is based upon grace, faith, and works.
We are not save by grace alone, faith alone, or works alone.
We are saved by grace, faith, and works.
Catholics have added penance and purgatory as a requirement for salvation and Protestants have subtracted works as a requirement of salvation.
Christ's sacrifice was sufficient to pay the penalty for sin and no penance or purgatory is necessary.
Works are a requirement for salvation but we are not saved by works alone. Paul says that we will be judged by our works and therefore works plays an important role in salvation. Nowhere does Paul say that we will be judged by our faith.
The Protestant doctrine of Sola Fide (faith alone) must be rejected because it directly contradicts the word of God. James, the brother of Jesus, clearly states that a man is not justified by faith alone.