'Be Strong' in the Bible

“I am going the way of all the earth [as dust to dust]. Be strong and prove yourself a man.

And the servants of the king of Syria said unto him, Their gods are gods of the hills; therefore they were stronger than we; but let us fight against them in the plain, and surely we shall be stronger than they.

And number thee an army, like the army that thou hast lost, horse for horse, and chariot for chariot: and we will fight against them in the plain, and surely we shall be stronger than they. And he hearkened unto their voice, and did so.