What is the significance of faith and humility when serving the Guru, as detailed in Chapter 16?

Chapter 16 of the Sai Satcharitra stresses that faith and humility are paramount in a disciple's service to the Guru. The text clarifies that while the Guru is an 'ocean of Truth, Consciousness, and Bliss' and beyond outward rituals, He enjoys them when performed with sincere faith. It is stated that an offering, even a simple leaf, given with faith is accepted lovingly, but if offered with pride, the Guru 'turns His face away.' Chapter 16 warns that any neglect or use of cleverness in service is detrimental, and that firm faith and humility are the only means to attain 'Sayujya' (union with Brahman) through the Guru's grace.