" When obedience becomes our goal, it is no longer an irritation; instead of a stumbling block, it becomes a building block." ~James E. Faust
I believe the quote means that people will push you to try your best and they are pushing you for the right reasons. Instead of being afraid you have to conquer your fear. If you don't really push yourself you're never gonna accomplish anything. If you do bad things like drinking and smoking you will stumble on the path of choosing the right and you won't ever be able to be good again.