If the outcome is good, it doesn't matter how you got it.
In other words, someone who believes this also believes that even if someone does immoral or even illegal things to achieve a good purpose, it's OK.
What does "The end justifies the means" means?
3 answers
It is an excuse for lying, cheating, or stealing, , or even murder in the name of doing a "greater" good. The term originated in the massacre of the Jesuits by Protestants (you can read about that), but there were other uses before that.
Are you reading Niccoló Machiavelli's The Prince by any chance?!