I'm new to Sai's teachings and feeling a bit skeptical. Can you share a story about how Baba dealt with a doubter?

Certainly. Chapter 35 tells the story of Boss Dharamsee, who visited Shirdi with a 'clinical scrutiny.' When offered grapes with seeds by Baba, Dharamsee was internally conflicted and doubtful, even questioning if Baba was a true saint for not knowing his dislike for them. As these thoughts arose, Baba gave him even more grapes. The story highlights how Baba, knowing Dharamsee's innermost thoughts, orchestrated a personal experience to address his skepticism directly. This encounter ultimately caused Dharamsee's ego to drop away and replaced his doubt with a profound love for the saint, demonstrating how Baba works on each individual according to their needs.