in the long run

Example 1:
Carly: I don't want to study anymore! I have been a student for too long! I should just quit school.
Mary: Carly! Don't be crazy! I know school can be difficult, but it will be worth it in the long run. Trust me.  
Carly: I know. You're probably right. 
Example 2:
Many children don't enjoy eating vegetables. It's important for parents to show children that eating a balanced diet will improve their overall health in the long run. Children may have trouble understanding this, and are only focused on the present. 
Meaning:
in the long run means in the future. This idiom is often used when the present situation is not ideal or is uncertain, as in examples 1& 2.
In example 1, Carly doesn't want to study now, but Mary reminds her that studying now will give her an advantage in the future.
In example 2, children don't know (or care) that vegetables will benefit them in the future. They are only concerned about the present. 
This idiom can be found in Reading Transitions. This book is used in the Level 4 Reading/Vocabulary class. To learn more, please visit idiomstudy.blogspot.com