'Bondage' in the Bible

Yet if the unbelieving departeth, let him depart: the brother or the sister is not under bondage in such cases : but God hath called us in peace.

For though I was free from all men, I brought myself under bondage to all, that I might gain the more.

but I buffet my body, and bring it into bondage: lest by any means, after that I have preached to others, I myself should be rejected.