'Needs' in the Bible

He that is born in thy house, and he that is bought with thy money, must needs be circumcised: and my covenant shall be in your flesh for an everlasting covenant.

And they said, Stand back. And they said again, This one fellow came in to sojourn, and he will needs be a judge: now will we deal worse with thee, than with them. And they pressed sore upon the man, even Lot, and came near to break the door.

And the servant said unto him, Peradventure the woman will not be willing to follow me unto this land: must I needs bring thy son again unto the land from whence thou camest?

And now, though thou wouldest needs be gone, because thou sore longedst after thy father's house, yet wherefore hast thou stolen my gods?