Sola fide, faith alone, is one of the bedrocks of the Reformation. We Protestants think we are different from our Catholic brethren in this, as we make the artificial distinction between “Us” and “Them.” “Us” being theologically sound Christians who know that we are saved not by any work, not by any effort on our part, but solely by faith in the living God and His Son, Jesus Christ.
“Them” being those, fill in you favorite negative adjective, error-prone Catholics and Orthodox who, we claim, cling to the notion that one may buy one’s way into heaven by good works.
It is well to remember that one reason Martin Luther split from Rome was the indulgences sold by the corrupt Vatican of the day: buying a ticket, as it were, into heaven. Good works, used in the manner of a bribe to God, are not markedly different. Good works, as a natural product of the faith that God has granted as a free gift, is quite different.
And here’s where we Protestants must not look on our Catholic brethren as somehow deficient. How do we know that a Catholic’s works are not the natural product of their God-given faith? Likewise, how do we know that a Protestant’s works are not really the product of faith, but, rather, the product of the need to show the world what good Christians we are?
Thomas Merton, a Trappist monk, said it well in Conjectures of a Guilty Bystander:To take one’s good works seriously is to be a pharisee.
Protestants must shake of their pharisiac notions, and remember what Jesus teaches in Luke 18:9-14: the moment we thank God that we are not like that Pharisee, we become him.