I meet Christians who are super-glossy, picture-perfect, law-abiding people, but they are absolutely miserable and difficult to be near. Their every movement is dictated by a strict rigid ruleset that is motivated by a desperate fear. If your efforts are not driven by grace — that God absolutely loves you no matter what — then you will punish yourself towards an invisible standard that looks like success but feels like slavery. Such a standard might work for a little while to conform your behavior, but it will never become a part of you: it’s just an apparatus that imprisons you. Only grace can truly be internalized to melt your heart, and though it can take longer, a truly tenderized heart follows God with all joy and perseverance. This is motivation by grace and grace alone.