be in a good cause

To have a beneficial, often charitable, aim or effect. Mom just wants to keep you out of trouble—her rules are in a good cause. Failure is always in a good cause, my dear, because it teaches you what not to do. I know $6 a cookie is a bit pricey, but this bake sale is in a good cause.

be (all) for/in a good ˈcause

worth doing, because it is helping other people: Most motorists seem to accept that the speed cameras are all in a good cause (= they help to keep people safe on the roads by stopping people driving too fast).