Intellectual: discussion is one of the most effective ways to make your class aware of the range of views on a given topic. This might be a place where discussion is helpful in assisting with a life application point you are making.
Emotional: discussion can be very helpful in helping your class to make an emotional connection to a given aspect of Scripture. For example, a lesson on Matthew 6:9-13 (the Lord’s Prayer) would benefit from taking a few minutes to share their personal experience with prayer in their lives.
Social: discussion can help your class grow closer together as members have the opportunity to hear others’ views and learn from one another.
I am a fan of class discussion as a means of helping to teach biblical truth. Adding/including a discussion component, once you’ve gotten your lesson moving, can be very helpful though you should have a fairly specific goal in mind (intellectual/emotional/social) as you’re preparing for your time with your class.As you’re thinking through the sorts of questions you might ask, keep in mind the question/s should tie back to the biblical truth you are teaching. In addition, when using discussion in your class, part of the lesson is helping the members of your class to understand the significance or importance of the particular question you’re discussing.