It's an easy concept to understand but not easy to implement.

It is not an easy concept to explain, but I will try.

For the upper class of the 17th, 18th and 19th centuries, diplomatic immunity was an easy concept to understand.

Unblinking service is not an easy concept in this country.

That is not an easy concept to grasp for Russian students.

This will not be an easy concept to impart, I fear.

Surely this is an easy concept to get your head around?

Why sacrifice was an easier concept to come to terms with than healing, I neither knew nor much wanted to know.

Going to a record store suddenly seemed like a very easy and progressive concept.

Vengeance was an easy concept, and forgiveness a difficult one, for a person with too little soul.