Land trying to be taken by Squatters rights

[Matt Whiteside]

My Parents own an 18 acre farm in southern, IL that used to belong to my great grandfather. There is a church that is next to the farm. My parents own a part of the grave yard, several relatives are buried there. Well a family took over the church several years ago. They are the ones who are trying to get that part of the land. There is also a group that takes care of several graves in the cemetery including our relatives.
Can they really use squatters rights to take this land form my parents?