Ninshū

is the religion and the peaceful precursor of modern Ninjutsu created Hagoromo Ōtsutsuki, the first one to understand and teach the mystery of chakra. The teachings of Ninshū were meant to give people a better understanding of themselves, as well as others, and lead the world into an era of peace. Ninshū would eventually come to be known as ninjutsu, a more weaponized version of the Sage's teachings.

Hagoromo exemplified his teachings by distributing chakra meant to "connect" people's spiritual energies with one another. It would allow people to understand each other without communication and would allow them pray for each other's safety. However people didn't use the chakra to connect with others, but to instead connect their inner spiritual and physical energies together. They kneaded their inner chakra to amplify it and transform it into modern-day Ninjutsu. Ironically, this was a byproduct of the time when Kaguya Ōtsutsuki, Hogoromo's mother, used chakra as a weapon.

Trivia

 * Naruto distributing his and Kurama's chakra to connect and protect his fellow Shinobi during the Fourth Shinobi World War bears many similarities to Hagoromo's original intent by originally distributing chakra as a whole.