for the sake of

1.  Also for one's sake. Out of consideration or regard for a person or thing; for someone's or something's advantage or good. For example, For Jill's sake we did not serve meat, or We have to stop fighting for the sake of family unity. [Early 1200s]
2.  For the purpose or motive of, as in You like to quarrel only for the sake of an argument [Early 1200s].
3.  for God's sake. Also for goodness or heaven's or Pete's or pity's sake. An exclamation showing surprise, impatience, anger, or some other emotion, depending on the context. For example, For God's sake, I didn't expect to see you here, or Hurry up, for goodness sake, or For heaven's sake, how can you say such a mean thing? or For pity's sake, finish your dinner. The variants are euphemisms for God. [c. 1300] For a synonym, see for the love of, def. 2.