The entire fabric of Spiritual discipline is briefly stated in this chapter, with Nondual Awareness as true devotion. It is a feeling of oneness with the Divine and this feeling is the true devotion which Lord Krishna is mentioning throughout the entire Bhagavad Gita.
Then having mentioned Nondual Awareness he mentions in descending order the graded discipline of Karma Yoga, which is a Yoga of action. This concept of Karma Yoga is outlined in four ways.
How to live a Spiritual life is outlined as the Spiritual Dharma to be enforced in life with thirty six ethical concepts.