Barker was keenly aware of the rising importance of New Thought and took an interest in preservation of early new thought history. He took a keen interest in gathering and publishing information about the earlier leaders of the New Thought movement. Barker supported the decision to create an archive at Southern Methodist University preseriving as much as possible of INTA's publications as well as the works by many early New Thought writers.

His book, Treat Yourself to Life was often used in Religious Science classes. Dr. Barker explains how to change the subconscious pattern through spiritual treatment. He is often quoted:

"There are unfortunately a great many people with attractive surface attitudes but with the same old rubbish underneath;"

"If you fail to direct your subconscious mind, it produces under a law of averages, and you are a nice, ineffective sweet person;"

"I call treatment mind surgery. It is the way in which you go into the subconscious, destroy old patterns and instill new ones."

He describes processes for treating the subconscious blocks which prevent individuals from attaining their goals. These treatments include everything from creating new ideas, eliminating problems, creating happiness, removing the belief of lack and limitation, how to decongest your consciousness and how to create a fresh mind!