The texts say Baba left his physical body, so how is it that devotees can still experience his presence and influence today?

Even though Sai Baba left his physical form, Chapter 43 teaches that he remains fully accessible to devotees. After merging into the unmanifest, he took up residence in the hearts of his followers, where he "always keeps the devotees awake." The scripture emphasizes that his presence is not diminished; in his true form, he fills the entire moving and non-moving world. Crucially, the experience of his presence is directly tied to the devotee's own state of mind. As Chapter 43 states, "Whatever the feeling in one's mind, such is the experience even today," confirming that his influence is proven and continues to operate based on the faith of the devotee.