Weighing the affairs and acting in accordance to the relative benefit and harm is probably the principle whose neglect is responsible for every fitnah that has befallen the Ummah of Islaam. So know it well, and do not fall into the traps that come along with ignorance of it!
So from the well-known Shareeżah principles is:
'Preventing mafsadah (harm) is given precedence over procuring maslahah (benefit).'
And 'ordering the good should not result in the loss of a greater good, nor cause a greater evil (than before). Likewise, forbidding the evil should not result in a greater evil, nor in the loss of a greater good.'