Sola fide

Today is commemorated as the day that German monk Martin Luther nailed his "95 theses" to the church door. The details may possibly be garbled, but there's no doubt that Luther shook up the Christian church. 

From his study of the Bible, he was convinced that the church had corrupted its message. For instance, "indulgences" were sold by the church with the promise of salvation through contribution to the building of a cathedral. Luther discovered that the Bible promised salvation through sola fide - faith in Christ alone, not money.

His conscience demanded that he fight the corruption. He was called before the pope and the emperor, and told to take it back or suffer the consequences. Here's his reply:

"Unless I am convinced by the testimony of the Scriptures or by clear reason (for I do not trust either in the pope or in councils alone, since it is well known that they have often erred and contradicted themselves), I am bound by the Scriptures I have quoted and my conscience is captive to the Word of God. I cannot and will not recant anything, since it is neither safe nor right to go against conscience. May God help me. Amen."

(from Wikipedia)