According to the source, what is the "most difficult and formidable" obstacle on the spiritual path, and how did Sai Baba help people overcome it?

According to the text of Chapter 35, the most "difficult and formidable" obstacle on the spiritual path is the "pride in one's own path." This pride manifested in people who believed their formless worship was superior and who judged saints like Sai Baba for having a form and accepting offerings. The chapter illustrates that Sai Baba helped people overcome this not with debate, but with direct experience. People arrived in Shirdi with firm resolutions rooted in this pride, but upon the "union of Darshan," they would forget their intellectual standpoints and spontaneously surrender at his feet. This shows that the direct, transformative experience of a Sadguru's presence can dissolve even the most formidable pride.