'Fail' in the Bible

If I go on preaching the Good News, that is nothing for me to boast of; for the necessity is imposed upon me; and alas for me, if I fail to preach it!

Charity never faileth: but whether there be prophecies, they shall fail; whether there be tongues, they shall cease; whether there be knowledge, it shall vanish away.

And so with you; if with the living voice you fail to utter intelligible words, how will people know what you are saying? You will be talking to the winds.