In chapters 1 and 2, the author of Hebrews showed that Jesus was not an angel. In fact, Jesus' role as Messiah required Him to be fully human. Starting in chapter 3, the author will explain how Jesus is also superior to various Old Testament characters such as Moses. This will help to set the stage for later references to Christ's superiority. Part of the warning in this chapter extends into chapter 4. Namely, that Christians who doubt God's promises risk missing out on the victories He has in store for us (BibleRef).