benefit, purpose, or interest
for God's/goodness/heaven's sake
used as an exclamation of protest, impatience, etc
for old times’ sake
because of or as an acknowledgment of a shared past; in memory of something in the past
for the sake of
in order to help or please (somebody); for their benefit
did it for the sake of the children
in order to achieve (some advantage)
do exercises for the sake of our health
[Old English sacu guilt, contention, in Middle English ‘accusation, one side's case in a legal action’; the current phrases date from the 13th cent. and prob come from Old Norse]