When teaching the gospel, he who asks the questions is in control. She who is being questioned has the power. This allows the Holy Ghost to work in harmony with the missionary (teacher). The Holy Ghost will do the heavy lifting when you, as the teacher, give permission to the investigator to think and express an opinion without fear of judgment.
Think about the last time you met a persuasive salesperson or missionary. Did you have permission to say no? Were your opinions, thoughts, and desires truly sought? Were they considered and honored? If no, did you feel trust towards that person?