Douglas Harper's Etymology Dictionary
bejesus
mild expletive, 1908, perhaps from by Jesus. To beat the bejesus out of someone is from 1934.
Wiktionary
bejesus
interj. Expressing surprise, annoyance, dismay, or anger. n. (context euphemistic English) Used for emphasis, similar to crap, shit or wits.
Usage examples of "bejesus".
On the karaoke stage, some tubby guy in snake boots was murdering the bejesus out of a Kenny Loggins song.
In the deep violet shadow of some crumbling grain silos near Gridley the panzer sweeps out of the darkness and scares the bejesus out of the sleeping kid in the cab of the fuel truck.
Townsend was kicking the bejesus out of a hastily built fire, thwarting the attempts of a couple of young men to rebuild it.