When a landing party from the USS Discovery visited his world in 2257, he was convinced that they were from Earth, but due to the fact that he was from a pre-warp culture, they lied to him, telling him they were from the Northern Territory so as to uphold the Prime Directive.
He still wasn't convinced however, and he used a flash grenade to knock them out, and he then locked them in the basement of the church and stole their utility bags to show to the All-Mother of the town, to prove to them that they are from outer space.
Amesha, the All-Mother, does not believe him however, and she tells him he is holding onto the old ways. He then returns the equipment that he stole from them and they take their leave, returning to the ship.
However, after a talk with Michael Burnham, Captain Christopher Pike decided to tell Jacob that he lied, and that he really was from Earth, because he wanted to learn more about the angel-like aliens that brought Jacob's ancestors to that planet. Jacob was happy that he finally got the answer that he had always wanted; proof that Earth still existed and wasn't destroyed two hundred years earlier as was previously believed. Jacob was then given a power cell by Captain Pike in exchange for the soldier's helmet camera. Using the power cell, Jacob was able to restore power to the church's light. It's uncertain whether he kept his encounter a secret from the others or not, but he told Pike that learning the truth was enough for him. (DIS: "New Eden")