Moralistic Therapeutic Deism has become a bit of a catch phrase in certain circles it comes from, Soul Searching: The Religious and Spiritual Lives of American Teenagers, a book by Christian Smith. I read it when I was in youth ministry and it shocked me. Most of our teens (and adults for that matter) don’t have a good view of what the Gospel really is.
This is a great video from the Resurgence. As someone who has worked in youth ministry I found the book Soul Searching that Dr. Horton refers to to be a shock. It is well worth the look.