What mantra does the text advocate for, and what is its stated power?

The text from Chapter 1 explicitly identifies 'Sai Samarth' as the mantra for devotees. Its power is described as immense, equating it to the devotee's Veda, scripture, yantra, and tantra. The name of the Guru, encapsulated in this mantra, is said to hold vast power that has been tested by those with selfless devotion. The passage suggests that devotion to this mantra and the Guru's name can unknowingly push devotees towards the doorstep of liberation, making it a central and potent practice that replaces the need for other complex rituals or extensive scriptural study.