The debate over justification by faith alone was the benchmark of the Reformation. The doctrine itself was said by Martin Luther to be “the article with and by which the church stands, without which it falls” (articulus stantis et cadentis ecclesiae). No single declaration was more prominent and more central to the Protestant movement than the declaration “sola fide!” (or faith alone). The validity of such a doctrine had major implications for the Roman Catholic Church, which stood to lose much in the way of funds and reputation.
When the reformers declared “sola fide,” they were directly opposing the Roman Catholic Church’s teachings on venial & mortal sins, priestly absolution, penance, and indulgences. While the reformers said that justification was gain by faith in Jesus Christ’s sacrifice, alone, and that the works of a man had no bearing on his justification, Rome taught that justification was gained when one possessed a faith “made perfect in love,” or a faith that was accompanied by “works.” Rome also believed that a person could lose his justification when he committed “mortal sins.” To regain justification, he had to confess to a priest, receive absolution, then commit acts of penance to regain favor with God.
In efforts to raise funds, Rome also sold indulgences (or stored-up merit from overly-righteous saints and leaders in the church) to those who felt they needed more righteousness to gain justification. Rome eventually marketed the indulgences as righteousness the people could buy for dead loved ones—in case they needed some extra righteousness to get out of purgatory. Johann Tetzel (a peddler of indulgences) claimed, “Every time a coin in the coffer rings, a soul from purgatory springs!” All of these acts (indulgences, penance, absolution, confession) were seen by the reformers as “works,” and were rejected as adding anything to justification. As Paul writes in Ephesians 2:8-9 “For by grace you have been saved through faith, and that not of yourselves; it is the gift of God, not of works, lest anyone should boast.”
Though the reformers declared that works did not contribute to justification, they believed that true faith always resulted in good works. In other words, works did not help justify a man, rather they were necessary results of his justification and faith. As James 2:17 states, “Faith by itself, if it does not have works, is dead.” The equation would thus look like this for the reformer:
Faith = Justification + Works
And the Roman Catholic view would be diagrammed like this:
Faith + Works = Justification
The placement of “Works” in these equations meant the difference between two entirely different systems of Theology. It was on this issue in the 16th century that the church was split and hundreds of Christians lost their lives, standing up for what they believed to be the true, biblical doctrine of justification.