Judges - Chapter 12

Here we read the origin of the word shibboleth:

The Gileadites captured the fords of the Jordan leading to Ephraim, and whenever a survivor of Ephraim said, “Let me cross over,” the men of Gilead asked him, “Are you an Ephraimite?” If he replied, “No,” they said, “All right, say ‘Shibboleth.’” If he said, “Sibboleth,” because he could not pronounce the word correctly, they seized him and killed him at the fords of the Jordan. Forty-two thousand Ephraimites were killed at that time."

Jesus is the only shibboleth for salvation:

If you declare with your mouth, “Jesus is Lord,” and believe in your heart that God raised him from the dead, you will be saved. (Romans 10)

Salvation is found in no one else, for there is no other name under heaven given to mankind by which we must be saved. (Acts 4)