It was in 1517 that Martin Luther posted his "95 Theses" to the big door of the church at Wittenburg, Germany. Ah, Luther, an early European Knight in the slaying of the dragon of Legalism.
This is often viewed as the beginning of what we call the Reformation. It was a giant blow against legalism, specifically the paying of money to the Roman Catholic Church for "indulgences" which were supposed to "buy off" years of purgatory. Purgatory is the Roman Catholic doctrine, totally unbiblical, that believers in Jesus Christ must undergo years of punishment for their own sins *after* death.
As awful as the legalistic doctrine is to begin with, even more awful was the teaching by church villains that one could buy their way into heaven faster (or that of Grandpa or Mom).
Thank God the light was shed on the great Gospel of Grace, showing that salvation is entirely of Grace, not of works, lest anyone should boast (Ephesians 2:8,9), and that we who believe in the Lord Jesus Christ are forgiven...past, present, and future, throught the sacrifice of our Lord.
Happy Reformation Day!