'Unless' in the Bible

And he said, “Well, how could I, unless someone guides me?” And he invited Philip to come up and sit with him.

Some men came down from Judea and began teaching the brethren, “Unless you are circumcised according to the custom of Moses, you cannot be saved.”

Paul said to the centurion and to the soldiers, “Unless these men remain in the ship, you yourselves cannot be saved.”