[5]: 10  Even as a child, he possessed an uncommon empathy that led others to seek out and trust his opinions and judgments in matters large and small.

Upon completing his schoolwork, he would often rush off to the village's Hanuman temple, where he and a childhood friend would listen to the discourses of a Hindu "holy man" named Haridas.

Those close to Shantilal felt it was only a matter of time until he would embark upon a monastic life by joining the order of Swaminarayan swamis under Shastriji Maharaj.

[5]: 11 Shastriji Maharaj gave Shantilal primary initiation, parshad diksha, at Ambli-Vadi Pol in Ahmedabad on 22 November 1939, and renamed him Shanti Bhagat.

"[5]: 17 Renouncing worldly pleasures, Shantilal adopted vows of celibacy (nishkam), non-covetousness (nirlobh), non-taste (nisswad), non-attachment (nissneh) and humility (nirman) and committed himself to lifelong dedication and service to God and humanity.

[13]: 61  In addition to his studies, Shastri Narayanswarupdas routinely engaged in a multitude of activities, including cleaning the temple compounds, cooking for swamis and devotees, and many other duties.

[14] Serving concurrently as Shastriji Maharaj's personal secretary, Shastri Narayanswarupdas also gained a comprehensive understanding of BAPS’ broader affairs and activities.

Twice Shastri Narayanswarupdas wrote back respectfully declining, citing his young age and inexperience, and the presence of many senior swamis who would be more suited to the responsibility.

[15] On 21 May 1950 at Ambli-Vali Pol in Ahmedabad, Shastriji Maharaj appointed Shastri Narayanswarupdas, then merely 28 years of age, as the administrative president ("Pramukh") of BAPS.

"[17] Despite being appointed the president of the organization just hours before, that evening, Shastri Narayanswarupdas was found washing the cooking utensils and dishes used by the devotees who had attended the ceremony.

[13] For instance, he helped Yogiji Maharaj in expanding the faith to England and East Africa in 1960 and 1970, constructing new temples, and instituting new programs within the organization.

As of 2019, BAPS encompasses over one million devotees, more than 900 swamis, 3,300 mandirs and congregations, over 7,200 weekly assemblies, and a host of humanitarian and charitable activities.

[19] He accompanied Yogiji Maharaj on a tour of East Africa in 1960[5]: 291  as well as in 1970, and embarked upon his first overseas visit as the guru, or spiritual leader, of BAPS in 1974.

[24] In discussing BAPS’ efforts to construct traditional Hindu temples around the world, Pramukh Swami emphasized the importance of such houses of worship in modern society and values and faith they inspire in members of the community.

Brian Hutchinson notes that in speaking with these individuals, the pramukh "consistently emphasizes what religions hold in common and advocates cooperation between them with the purpose of uplifting the moral and religious life of mankind".

[28][29] His response and guidance during those times was commended by leaders and commentators, including the National Security commando in charge of the rescue mission during the Akshardham attack, who later asserted that "what [the pramukh] did was unbelievable.

[30] He led BAPS’ efforts in conducting a number of large-scale cultural festivals, with the aim of fostering better understanding and appreciation of Hindu traditions and promoting moral and spiritual living.

However, due to his longstanding heart problems, he died on 13 August 2016, at 6 pm at the BAPS Swaminarayan Mandir, Sarangpur, Botad district, Gujarat, India.

[13]: 87–95 The living guru is considered by followers of BAPS to be the ideal swami, the perfect devotee, and the principal target for emulation by all spiritual aspirants.

[38]: 153  His conduct was hence considered to be that of the "ideal saint" and "perfect bhakta (devotee)", providing a tangible and graspable example for the spiritual aspirant to follow.

[38]: 150  Similarly, devotees viewed his actions in September 2002, when he appealed for peace and forgiveness of Muslim militants who killed 32 people and injured dozens more in an attack on Akshardham Gandhinagar, to epitomize the Hindu tenet of ahimsa, or nonviolence.

[38] Earning the grace of the guru, devotees believed, would enable them to achieve liberation in which they would escape the cycle of births and deaths and attain "Akshardham" (God's divine abode).

[38] Williams notes that devotees trust Pramukh Swami's advice due to his theological role as guru and manifestation of Akshar, but also because "as a world-renouncer, he is impartial and gains no personal advantage from helping them with decisions.

"[42]: 108 Pramukh Swami had said that the purpose of his providing advice on such a range of matters was not to establish the devotees in business or to enable them to become wealthy, but to relieve them of anxieties about mundane affairs so they could attend to their spiritual progress.