This quote from Tullian Tchividjian is insightful.
“The ironic thing about legalism is that it not only doesn’t make people work harder, it makes them give up.”
I’ve seen the performance-ism brand of legalism take the wind out of the spiritual sails of people close to me. Gospel-lite performance-ism leads to either prideful living marked by a critical spirit, or discouragement and eventually, despair. Both are sad to see, but the beauty and power of grace is its ability to restore, heal, and make all things new.