What is the primary method for attaining spiritual knowledge, according to the teachings of Dnyaneshwar Maharaj cited in the text?

According to the teachings of Lord Samarth Sadguru Dnyaneshwar Maharaj referenced in Chapter 0, the primary path to spiritual knowledge is through dedicated service to the saints. The text states, "Where the treasure of knowledge resides, service is the doorway." To receive this wisdom, one is instructed to serve with their entire being—body, mind, and soul—and to perform all service without ego. It is through this selfless surrender at their feet that the saints will impart knowledge that enlightens the heart and ensures that doubts will not arise.