'Unless' in the Bible

Remember therefore from where you have fallen, and repent and do the first works; or else I am coming to you swiftly, and will move your lampstand out of its place, unless you repent.

Behold, I will throw her into a bed, and those who commit adultery with her into great oppression, unless they repent of her works.

and that no one would be able to buy or to sell, unless he has that mark, the name of the beast or the number of his name.