'Unless' in the Bible

The man replied, "How can I unless someone guides me?" So he invited Philip to get in and sit with him.

Then some men came down from Judea and started to teach the brothers, "Unless you are circumcised according to the Law of Moses, you can't be saved."

unless it is for the one thing I shouted as I stood among them: "It is for the resurrection of the dead that I am on trial before you today.'"

Paul told the centurion and the soldiers, "Unless these men remain onboard, you cannot be saved."