You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Martin_Luther

Context:
From 1510 to 1520, Luther lectured on the Psalms, the books of Hebrews, Romans, and Galatians. As he studied these portions of the Bible, he came to view the use of terms such as penance and righteousness by the Catholic Church in new ways. He became convinced that the church was corrupt in its ways and had lost sight of what he saw as several of the central truths of Christianity. The most important for Luther was the doctrine of justification – God's act of declaring a sinner righteous – by faith alone through God's grace. He began to teach that salvation or redemption is a gift of God's grace, attainable only through faith in Jesus as the Messiah. "This one and firm rock, which we call the doctrine of justification," he wrote, "is the chief article of the whole Christian doctrine, which comprehends the understanding of all godliness."

Question:
What did Martin Luther do during 1510 to 1520?

lectured