How did the author Hemadpant's initial humility and deep, unwavering faith make him the ideal choice to write Sai Baba's biography from the start?

According to the account in Chapter 2, the premise of this question is incorrect. The author did not begin with humility and unwavering faith. He describes his initial state quite differently, stating he was "mischievous, talkative, cynical, and critical." He also admits to having a "bad intellect and a logic-driven mind" and being "proud of his own wisdom." It was Sai Baba's instruction for him to dissolve this ego and surrender it at His feet. The promise was that only after this surrender would Sai Baba provide full assistance and essentially write the story through him.