Sant Mat's central teaching is surat shabd yoga, the union of the soul (surat) with the divine sound current (shabd). The practice rests on the belief that the divine has an audible and visible form accessible through inward attention, reached by withdrawing awareness from the body's outer senses to a point of concentration and then following the current inward and upward through a sequence of inner regions toward its source. Different lineages describe that sequence differently, but the underlying method, a living master's guidance, a private initiation, and a daily practice of meditation, is shared across nearly all of them.
The tradition places its authority in a living master rather than in scripture alone. A master is understood to have completed the inward journey and to be able to guide a disciple along it, which is why initiation by a recognized living teacher, not the reading of a text, is what a follower understands to actually begin the practice. This is also why Sant Mat has produced repeated succession disputes: when a master dies, followers who accept different successors as legitimate become, in effect, separate organizations, which is the pattern David Lane's scholarship traces across the Radhasoami movement's history from Shiv Dayal Singh's death onward, at Agra, Beas, Tarn Taran, Hoshiarpur and Delhi.
Sant Mat's older roots lie in the North Indian sant tradition of poet-teachers such as Kabir and Guru Nanak, who taught an inward, formless devotion against external ritual and social distinction centuries before Shiv Dayal Singh founded Radhasoami in 1861. The modern lineages read themselves as continuing that older current rather than as an entirely new teaching.