This passage gives the reason for the apostle’s writing this letter, the reason we have this part of God’s inspired word. It is so that “people will know how to conduct themselves in the household of God.” The letter is written so that we will know how to conduct ourselves as God’s family, His church. We will see that our conduct arises from who we are in Christ and what we believe about Christ. In this short passage we have a beautiful description of who we are as the church and a concise statement of the belief that shapes us.