'Warning' in the Bible

And in this they became a warning to us, to teach us not to be eager, as they were eager, in pursuit of what is evil.

Those who persist in sin reprove in the presence of all, so that it may also be a warning to the rest.

seeing that the warning still comes to us, "To-day, if you hear His voice, do not harden your hearts as your forefathers did in the time of the provocation."