'Unprofitable' in the Bible

Should he reason with unprofitable talk? or with speeches wherewith he can do no good?

And cast ye the unprofitable servant into outer darkness: there shall be weeping and gnashing of teeth.

So likewise ye, when ye shall have done all those things which are commanded you, say, We are unprofitable servants: we have done that which was our duty to do.

They are all gone out of the way, they are together become unprofitable; there is none that doeth good, no, not one.

But avoid foolish questions, and genealogies, and contentions, and strivings about the law; for they are unprofitable and vain.

Which in time past was to thee unprofitable, but now profitable to thee and to me:

Obey them that have the rule over you, and submit yourselves: for they watch for your souls, as they that must give account, that they may do it with joy, and not with grief: for that is unprofitable for you.