One of the classic examples of Jesus using a question to teach is found in Luke 9.18 where Jesus says, “Who do the crowds say that I am?”
Why did Jesus ask this? Did he not know? That could be. When he became human he set aside some of his god-ness. In another context he said he did not know the day or the hour when he would return. I think it is more likely, however, that it was a teaching moment for the disciples. Jesus knew that when Peter declared Jesus to be, “the Christ of God” that Peter would be change by this declaration.
Jesus taught that we are changed as much by what we say as what we hear. Mark 7:15 (NIV) “Nothing outside a man can make him ‘unclean’ by going into him. Rather, it is what comes out of a man that makes him ‘unclean.’” “What comes out of a man”—what a man speaks is that makes him clean. We are changed by the truth when we speak the truth. When Peter declared Jesus to be the Christ, he believed ever more firmly that Jesus was the Christ.
This is why the Bible makes a big deal about “if you confess with your mouth.” (Romans 10.9) It is not that God needs to hear. It is not even that others need to hear. It is that you need to say. When you confess the truth with your mouth, you are changed by that truth.
Whey I write Sunday School lessons, they are mostly questions. Good Questions help us to teach like Jesus.