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:
On the other hand, Luther also points out that the Ten Commandments – when considered not as God's condemning judgment but as an expression of his eternal will, that is, of the natural law – also positively teach how the Christian ought to live. This has traditionally been called the "third use of the law." For Luther, also Christ's life, when understood as an example, is nothing more than an illustration of the Ten Commandments, which a Christian should follow in his or her vocations on a daily basis.

Question:
Teaching Christians how they should live is what use of the law?

third use of the law