'Bond servant' in the Bible

Jesus answered them, Verily, verily, I say unto you, Every one that committeth sin is the bondservant of sin.

And the bondservant abideth not in the house for ever: the son abideth for ever.

Wast thou called being a bondservant? Care not for it: nay, even if thou canst become free, use it rather.

For he that was called in the Lord being a bondservant, is the Lord's freedman: likewise he that was called being free, is Christ's bondservant.

But I say that so long as the heir is a child, he differeth nothing from a bondservant though he is lord of all;

So that thou art no longer a bondservant, but a son; and if a son, then an heir through God.