1
general::
Under good or bad circumstances, with good or bad effect. For example, For better or for worse he trusts everyone. This term became widely familiar because it appears in the marriage service of the Book of Common Prayer (1549): "With this ring I thee wed, for richer or poorer, in sickness and in health, for better or worse, til death do us part." [Late 1300s]
American Heritage Idioms
2
general::
Phrase(s): for better or for worse
under any conditions; no matter what happens. • I married you for better or for worse. • For better or for worse, I’m going to quit my job.
McGrawhill's American Idioms And Phrasal Verbs