'Be Strong' in the Bible

And the fourth kingdom shall be strong as iron, inasmuch as iron breaks in pieces and subdues all things. And as iron that crushes all these, it shall break in pieces and crush.

And he said, O man greatly beloved, fear not. Peace be to thee. Be strong, yea, be strong. And when he spoke to me, I was strengthened, and said, Let my lord speak, for thou have strengthened me.

And the king of the south shall be strong, and [one] of his rulers. And he shall be powerful over him, and have dominion. His dominion shall be a great dominion.

And he shall pervert by flatteries such as do wickedly against the covenant. But the people who know their God shall be strong, and do [exploits].