There will be a lot of talk of hammers in Christian churches this weekend.

500 years ago, on October 31, 1517, a young Catholic monk named Martin Luther took a hammer and nailed a list of 95 “Theses,” or arguments, to the door of the Wittenberg Castle church in Germany. The arguments centered on practices in the Church that Luther felt went beyond its authority, supplanting the authority of God. No one could have known where it would lead.

Today, Luther’s action is generally considered to be the moment of the beginning of the Protestant Reformation, which has had a profound impact on Christianity, western civilization, and the whole world.  And after 500 years, it’s a monk with hammer in hand that has come to symbolize that moment.

Luther’s timing was perfect. With the help of Johannes Gutenberg’s new printing press, copies of Luther’s document spread throughout Germany in two weeks, and across Europe in two months.

In his document, Martin Luther formally challenged church leaders on the practice of selling indulgences and outlined the biblical doctrine of justification by grace alone. His rallying cry became, “The just shall live by faith” (Romans 1:17, KJV). And Martin Luther was changed from a German monk with questions in his heart to the reformer most closely associated with the birth of Protestantism.

Luther’s courageous actions were guided by another Bible verse, which says, “We ought to obey God rather than men” (Acts 5:29). Luther’s insistence on sola scriptura—the Bible as the only authority for faith—is a cornerstone of the Protestant Reformation and fundamental to my own Adventist faith.

For Protestants, the 500th anniversary of the beginning of the Reformation offers a special opportunity for reflection and renewal. May our own experience parallel that of Luther himself, who wrote, “When I discovered that [sola scriptura], I was born again of the Holy Ghost.  And the door of paradise swung open, and I walked through.”

The ring of Luther’s hammer on the door of the church can still be heard.